JPS5949451B2 - Shift control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shift control device for an automatic transmission.

The purpose of the present invention is to: upon upshifting of an automatic transmission;
The purpose is to smoothly perform a switching operation between releasing a low-speed friction element and locking a high-speed friction element, thereby facilitating a smooth upshift.

More specifically, when the input torque is large and the internal pressure of the high-speed friction element is below a predetermined value, the pressure oil in the low-speed friction element is gradually discharged through the orifice.
When the internal pressure reaches a predetermined value or more, the pressure oil of the low-speed friction element is immediately discharged without going through the orifice, thereby establishing a temporal relationship between the engagement and release of the low-speed friction element and the high-speed friction element. If the relationship is such that they overlap appropriately, slippage will occur in both friction elements, resulting in smooth gear changes with little torque fluctuation.

In addition, when the input torque is low and the throttle is fully closed, if the pressure oil in the low-speed friction element is quickly discharged without going through the orifice, the low-speed friction element can be released more quickly than the high-speed friction element is engaged. This ensures smooth gear shifting without shock.

The present invention consists of an input shaft, an output shaft, a planetary gear mechanism provided between the two shafts, and a plurality of friction elements including a friction clutch or a friction brake, and the friction elements are appropriately engaged or released by hydraulic pressure. In an automatic transmission that can obtain a gear ratio of multiple forward speeds and one reverse speed, a hydraulic power source, a pressure regulating valve that controls the hydraulic pressure generated by the hydraulic power source, and a pressure regulating valve that is controlled by the operation of the pressure regulating valve. Low-speed and high-speed hydraulic chambers that introduce line pressure to operate the low-speed and high-speed friction elements, a governor valve that generates governor pressure as a function of vehicle speed, and throttle pressure as a function of driving engine load. a throttle valve that is switched and controlled according to the governor pressure to supply line pressure to the high-speed hydraulic chamber when the governor pressure is equal to or higher than a predetermined value, and also communicates the low-speed hydraulic chamber to the discharge oil passage. a first discharge passage that is in constant communication with a discharge oil passage of the low-speed hydraulic chamber; and a first discharge passage that is configured to control communication between the first discharge passage and the discharge oil passage of the low-speed hydraulic chamber; a switching valve having a second discharge path with a flow path area larger than the first oil chamber, and the switching valve is supplied with hydraulic pressure when the first oil chamber communicates with the high-speed hydraulic chamber and the throttle valve is fully closed. and a second oil chamber configured to cut off communication between the second discharge passage and the discharge oil passage when hydraulic pressure is not supplied to the both arm chambers, and to shut off communication between the second discharge passage and the discharge oil passage; The discharge oil passage has a structure that allows the second discharge passage and the discharge oil passage to communicate with each other when hydraulic pressure is supplied.

Furthermore, after the shift valve is switched during gear shifting, when the throttle valve is not in a fully closed state, the low-speed hydraulic chamber is communicated only with the first discharge passage, and the hydraulic pressure in the high-speed hydraulic chamber is transferred to the switching valve. The low-speed hydraulic pressure chamber is made to communicate with the second discharge path, and when the throttle valve is fully closed, the switching valve is caused to control the low-speed hydraulic pressure by the hydraulic pressure supplied to the second oil chamber. It has a structure that allows the chamber and the second discharge path to communicate with each other.

Further, the first discharge path has a structure including an orifice.

Next, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, the automatic transmission of the present invention includes an output shaft 1 of a prime mover, a torque converter 20, an input shaft 2, intermediate shafts 3 and 4, planetary gear mechanisms 30 and 40, an output shaft 5, clutches 10 and 11, and a brake 12. 13, one-way clutch 14, etc.

The torque converter 20 consists of a pump impeller 21, a turbine runner 22, a one-way clutch 24, and a stator 23 supported by the pump impeller 21. The stator 23 controls the flow of fluid when the speed difference between the pump impeller 21 and the turbine runner 22 is large. The rectification is performed to output a larger torque than the input torque to the turbine runner 22.

The planetary gear mechanisms 30.40 each have a sun gear 31.41, a planetary pinion 32.42, a ring gear 33.43 and a carrier 34.44.

An output shaft 1 of the prime mover is connected to a pump impeller 21 of a torque converter 20, and a turbine runner 22 of the torque converter 20 is connected to an input shaft 2.

A clutch 10 is provided between the input shaft 2 and the intermediate shaft 3, and a clutch 11 is provided between the input shaft 2 and the intermediate shaft 4.

The intermediate shaft 3 is connected to a ring gear 43 of a planetary gear mechanism 40, and the intermediate shaft 4 is connected to a sun gear 31.40 of a planetary gear mechanism 30.40.
41 and is provided with a brake 12.

The output shaft 5 is connected to a ring gear 33 of a planetary gear mechanism 30 and to a carrier 44 of a planetary gear mechanism 40.

The carrier 34 of the planetary gear mechanism 30 is the one-way clutch 14
and a brake 13.

Table 1 summarizes the operations of the clutch 10.11, brake 12.13, and one-way clutch 14 at each gear stage of the automatic transmission of the present invention having such a configuration.

In Table 1, the ○ mark indicates that the hydraulic oil operating mechanism is operating.

The Δ mark indicates that the engine brake is being operated by the pressurized oil operating mechanism when necessary.

* indicates that the one-way clutch is locked only when the engine is driving.

FIG. 2 is a hydraulic circuit showing an embodiment of the hydraulic control device of the present invention.

This hydraulic control device includes an oil reservoir 100, an oil pump 101, a pressure regulating valve 200, a speed selection valve 210, and a -2 shift valve 220.
．． 2-3 Shift valve 230, throttle valve 240, cutback valve 250, governor valve 260, switching valve 270.28
0, a hydraulic cylinder 310 which is a hydraulic chamber of a hydraulic piston that operates various valves such as a relief valve 290 and a check valve 300, as well as other clutches 10.11 and brakes 12.13.
．． 320, 330, 340, and other various valves and various hydraulic circuits arranged between the hydraulic cylinders.

The operation of this hydraulic control device will be explained below.

The source of the hydraulic pressure for the hydraulic control device, hydraulic oil for the torque converter 20, and lubricating oil for each part is an oil pump 101, which is directly driven by the engine to draw oil from the oil reservoir 100 and into the oil passage 102. It is ejected to.

The oil pressure in the oil passage 102 is the source of all working oil pressure and is called line pressure.

The line pressure is adjusted to a predetermined pressure by a pressure regulating valve 200 as described later.

The relief valve 290 is a relief valve when the line pressure becomes abnormally high.

Oil is supplied from oil passage 103 to torque converter 20 and each lubricating location through pressure regulating valve 200 .

The speed selection valve 210 consists of a spool 211 that is moved by operating the driver's seat lever, and depending on the lever selection position, the line pressure of the oil passage 102 is adjusted to the oil passage 104.10 as shown in Table 2.
It serves as a guide to 5.106.107.

The ○ mark in Table 2 indicates that line pressure is guided to the oil passage marked by ○ at each selected position, and the - mark indicates that line pressure is not guided to the oil passage marked in that column at the selected position. represent.

The operation of the transmission at each position is: R position is reverse, N position is neutral, D position is forward 3-speed automatic transmission, 2 position is 1st forward speed, automatic transmission between 1st and 2nd speed, L position is forward transmission. This is the 1st gear fixed position.

In the D position, line pressure is sent from the oil passage 104 to the hydraulic cylinder 310, and the clutch 10 is always engaged.

Oil passage 104 also leads line pressure to 1-2 shift valve 220 and governor valve 260.

The 1-2 shift valve 220 consists of a spool 221, 222 and a spring 223, and in the first gear, the non-spool 221
is located below and does not guide line pressure to any of the oil passages 104.

In the second and third speeds, the spool 221 is moved upward due to the action of the governor pressure from the oil passage 111.
04 line pressure is guided to the oil passage 112.

The oil passage 112 communicates with the 2-3 shift valve 230, and when the spool 231 of the 2-3 shift valve 230 is located at the lower position in the figure, the line pressure of the oil passage 112 is guided to the oil passage 113, and the oil pressure of the brake 12 is changed. Line pressure is sent to the cylinder 330 to operate the brake 12.

When the brake 12 is engaged, the power transmission mechanism enters the second speed state as shown in Table 1.

The 2-3 shift valve 230 consists of spools 231, 232 and a spring 233, and in the 1st and 2nd speeds, the spool 231 is located lower in the figure, and in the 3rd speed, the oil passage 111
The spool 231 moves upward in the figure due to the action of the governor pressure from
4, and sends line pressure to the hydraulic cylinder 320 of the clutch 11 to operate the clutch 11, and at the same time, the oil line 11
3 to the oil passage 115, the line pressure in the hydraulic cylinder 330 is discharged via the oil passage 113, 115 and the switching valve 280, and the brake 12 is released.

When the clutch 11 is engaged and the brake 12 is released,
As shown in Table 1, the power transmission mechanism is in the third speed state.

In the second position, line pressure is supplied to oil passage 104 and oil passage 105.

The line pressure led to the oil passage 105 is transferred to the 2-3 shift valve 230.
The spools 231 and 232 are guided to the oil chamber 234 and held at the lower position in the figure.

The line pressure of the oil passage 104 is applied to the hydraulic cylinder 3 of the clutch 10.
10 and the 1-2 shift valve 220.

1-2 When the shift valve 220 is not in the 1st speed state, the oil path 1
The line pressure of 04 is led to the hydraulic cylinder 330 via oil passages 112 and 113, and the brake 12 is engaged.

When the clutch 10 and brake 12 are engaged, the power transmission mechanism enters the second speed state as shown in Table 1.

When the 1-2 shift valve 220 is in the first speed state, the spool 221 is located at the lower side in the figure, and the oil passage 112 is connected to the oil drain port 225.
The pressure oil in the hydraulic cylinder 330 is connected to the oil passage 113.
．． The oil is discharged from the drain port 225 through the brake 1
2 is released, and the power transmission mechanism enters the first speed state.

In the L position, line pressure is introduced into oil passages 104, 105, 106.

The line pressure introduced into the oil passage 104 operates the clutch 10 in the same manner as in each gear position at the D position.

The line pressure led to the oil passage 105 is transferred to the 2-3 shift valve 230.
The spools 231 and 232 are held at the lower side as shown in the figure.

The line pressure led to the oil passage 106 is transferred to the 1-2 shift valve 220.
It acts on the oil chamber 224 of the brake 1 to hold the spools 221 and 222 at the lower position in the figure, and also
3 to actuate the brake 13.

When the brake 13 is actuated, the carrier 34 of the planetary gear mechanism 30 is fixed in any direction of rotation, so that so-called engine braking becomes effective.

When the clutch 10 and the brake 13 are engaged in this manner, the power transmission mechanism enters the first speed state as shown in Table 1.

In the R position, line pressure is introduced into oil passages 106, 107.

The line pressure led to the oil passage 107 is led to the oil chamber 206 of the pressure regulating valve 200 and acts to increase the line pressure, and is also led to the oil m114 via the 2-3 shift valve 230 to operate the clutch 11. let

Further, the line pressure of the oil passage 107 is guided to the oil passage 116 via the 1-2 shift valve 220 to operate the brake 13.

When the clutch 11 and the brake 13 are engaged in this manner, the power transmission mechanism enters the reverse state as shown in Table 1.

The governor valve 260 consists of a governor valve 261, a governor weight 262, a governor shaft 263, a spring 264, and an oil chamber 265, and is attached to the output shaft 5 in FIG. 1.

The governor valve 260 includes a governor valve 261, a governor weight 262, a governor shaft 263, and a spring 264.
The centrifugal force acting on the spring 264 and the oil chamber 2
In balance with the hydraulic pressure acting on the output shaft 65, a hydraulic pressure (governor pressure) is generated in the oil passage 111 that is a function of the output shaft rotational speed, that is, a hydraulic pressure (governor pressure) that increases as the output shaft rotational speed increases.

The throttle valve 240 includes a spool 241, a downshift plug 242, springs 243, 244, and an oil chamber 245.
246, the balance between the force of the spring 244 due to the movement of the downshift plug 242 in conjunction with the movement of the accelerator pedal and the force of the hydraulic pressure acting on the oil chamber 245, 246 causes the oil passage 108 to have a throttle valve proportional to the throttle opening. It is generating pressure.

The throttle pressure in the oil passage 108 is communicated to the 1-2 shift valve 220 and the 2-3 shift valve 230, and controls the timing of gear changes according to the engine load state.

Also, when kickdown is necessary, if the accelerator pedal is strongly depressed, the downshift plug 242 moves upward and the oil passage 102 communicates with the oil passage 109, and the line pressure of the oil passage 102 passes through the oil passage 109 to the 1-2 shift valve 220. .2-3. From the third speed to the second speed due to the governor pressure guided by the shift valve 230 and acting on the lower end of the spool 221.231,
Or downshift from 2nd gear to 1st gear.

The cutback valve 250 has a spool 251, an oil chamber 252.
253, the pressure oil acting on the oil chamber 252 and the oil chamber 25
A cutback pressure is generated in the oil passage 110 due to the balance with the pressure oil acting on the oil passage 110.

The cutback pressure in the oil passage 110 acts on the throttle valve 240 to lower the throttle pressure and prevent unnecessary power loss due to the oil pump.

The pressure regulating valve 200 consists of a spool 201, 202, a spring 203, an oil chamber 204, 205, 206, and an orifice 207 provided at the entrance of the oil chamber 204.
4. Pressure oil and spring 203 acting on 205.206
Line pressure is generated in the oil passage 102 in balance with the force of.

The switching valve 270 includes a spool 271, a spring 272,
It consists of an oil chamber 273 and controls communication between the oil passage 102 and the oil passage 117 in relation to the magnitude of the throttle pressure acting on the oil chamber 273.

When the throttle opening is zero, no throttle pressure acts on the oil chamber 273, and the spool 271 is positioned upward in the drawing by the spring 272, communicating the oil passage 102 and the oil passage 117.

When throttle pressure is generated in the oil chamber 273, the spool 27
1 moves downward in the figure against the spring 272 and opens the oil passage 1.
02 and the oil passage 117 are cut off, and the oil passage 117 is connected to the outlet 2.
Contact 74.

The switching valve 280 consists of a spool 281, a plug 282, a spring 283, and oil chambers 284 and 285.
．． The balance between the pressure oil acting on the oil passage 285 and the force of the spring 283 switches between connecting the oil passage 115 to a discharge passage 286 having an orifice 288 or connecting the oil passage 115 to a discharge passage 287 having no orifice. .

Next, hydraulic control at the time of 2-3 shift up, which is the gist of the present invention, will be explained.

During the second forward speed, line pressure is guided to the oil passage 112 and supplied to the hydraulic cylinder 330 through the oil passage 113 via the 2-3 shift valve 230, and the brake 12 is engaged.

When the vehicle speed increases from this state and the spool 231 of the 2-3 shift valve 230 moves upward in the drawing, the oil passage 112 is connected to the oil passage 114 and the oil passage 113 is connected to the oil passage 115.

The line pressure in the oil passage 112 is controlled by the oil passage 114 and the check valve 30.
The oil is gradually guided to the hydraulic cylinder 320 of the clutch 11 through the orifice 301 and the oil passage 118.

Further, the pressure oil in the hydraulic cylinder 330 of the brake 12 is discharged through the oil passages 113 and 115 and the switching valve 280.

The oil passage 118 communicates with the oil chamber 285 of the switching valve 280, and when the internal pressure in the hydraulic cylinder 320 is below a predetermined value, the spool 281 of the switching valve 280 is connected to the spring 28.
3, the oil passage 115 is connected to the orifice 2.
A hydraulic cylinder 330 is connected to a discharge passage 286 having a hydraulic cylinder 330.
The pressure oil inside is gradually discharged through oil passages 113 and 115 and orifice 288.

When the internal pressure in the hydraulic cylinder 320 exceeds a predetermined value, the spool 281 of the switching valve 280 releases the spring 283.
It moves to the right in the figure against the pressure, connects the oil passage 115 to the discharge passage 287 without an orifice, and quickly discharges the pressure oil in the hydraulic cylinder 330 via the oil passage 113, 115 and the discharge passage 287.

When the input torque is large as described above, by providing an appropriate overlap between the engagement of the clutch 11 and the release of the brake 12, the clutch 11 and the brake 12 slip, resulting in a smooth shift with less torque fluctuation.

In addition, when the throttle is fully closed with low input torque, the pressure oil in the oil passage 102 is guided to the oil chamber 284 of the switching valve 280 via the switching valve 270 and the oil passage 117, and the spool 281
, the plug 282 is moved to the right in the figure against the spring 283 to connect the oil passage 115 to the discharge passage 287 without an orifice.

The pressure oil in the hydraulic cylinder 330 is immediately transferred to the oil passage 11 when the spool 231 of the 2-3 shift valve 230 moves upward in the figure.
3.115, since it is quickly discharged through the discharge path 287, the brake 12 is released more quickly than the clutch 11 is engaged.

In this way, when the input torque is low and the throttle is fully closed, the brake 12 is released earlier than the clutch 11 is engaged, so that smooth gear changes are performed without shock.

FIG. 3 is a hydraulic circuit showing another embodiment of the hydraulic control device of the present invention, in which the detection of the throttle fully closed state is performed using the switching valve 270.
This is done by the throttle valve 240 instead.

According to this, when the throttle is fully closed, the downshift plug 242 of the throttle valve 240 is in the illustrated position, communicating the oil passage 102 and the oil passage 119.

Pressure oil in the oil passage 102 is guided to the oil chamber 284 of the switching valve 280 through the oil passage 119.

Furthermore, when the throttle valve 240 is open, communication between the oil passage 102 and the oil passage 119 is cut off, and the pressure oil in the oil chamber 284 of the switching valve 280 is discharged through the orifice 120.

In this way, the signal indicating the throttle fully closed state is transmitted to the switching valve 28.
0.

Note that this operation is the same as that in FIG. 2, so a description thereof will be omitted.

As described above, the present invention relates to a shift control device for an automatic transmission, and particularly to a control system for the timing of engagement and release of clutches and brakes during a 2-3 shift up.

According to the present invention, when the input torque is large, the engagement and release of the clutch and brake are overlapped, and when the input torque is low and the throttle is fully closed, the brake is released earlier than the clutch is engaged. This prevents shock during gear shifting and allows for smooth gear shifting.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the power transmission mechanism of an automatic transmission to which the present invention is applied, Fig. 2 is a hydraulic circuit diagram showing an embodiment of the hydraulic control device of the present invention, and Fig. 3 is a hydraulic circuit diagram showing an embodiment of the hydraulic control device of the present invention. FIG. 3 is a hydraulic circuit diagram showing another embodiment of the control device. Explanation of symbols: 1... Output shaft of prime mover, 2... Input machine, 3° 4... Intermediate shaft, 5... Output shaft, 10... Clutch, 11... Clutch (for high speed) frictional element), 12
... Brake (low-speed friction element), 13... Brake, 14... One-way clutch, 20... Torque converter, 30.40... Planetary gear mechanism, 100...
Oil reservoir, 101...Oil pump (hydraulic source), 113...
- Oil passage (hydraulic chamber for low speed), 118... Oil passage (hydraulic chamber for high speed), 200... Pressure adjustment valve, 210... Speed selection valve, 220... 1-2 shift valve, 230 2-3 shift valve, 240... throttle valve, 250... cutback valve, 260... governor valve, 270... switching valve, 280... switching valve, 290... IJ IJ-F valve, 300...Check valve, 310.320.330
．． 340... Hydraulic cylinder, 286... Discharge path (first discharge channel), 287... Discharge channel (second discharge channel),
288.120... Orifice.

Claims (1)

[Scope of Claims] 1 Consists of a human power shaft, an output shaft, a planetary gear mechanism provided between the two shafts, and a plurality of friction elements including a friction clutch or a friction brake, and the friction elements are appropriately engaged by hydraulic pressure. Or, in an automatic transmission in which a gear ratio of multiple forward speeds and one reverse speed can be obtained by releasing the gear ratio, a hydraulic pressure source, a pressure regulating valve that controls the hydraulic pressure generated by the hydraulic pressure source, and the operation of the pressure regulating valve. low-speed and high-speed hydraulic chambers that introduce controlled line pressure to operate the low-speed and high-speed friction elements; a governor valve that generates a governor pressure that is expressed as a function of vehicle speed; and a governor pressure that is expressed as a function of drive engine load. It will be done. a throttle valve that generates throttle pressure; and a hydraulic line that is switched and controlled according to the governor pressure to supply line pressure to the high-speed hydraulic chamber and discharge the low-speed hydraulic chamber when the governor pressure is equal to or higher than a predetermined value. and a first shift valve that communicates with the discharge oil passage of the low-speed hydraulic chamber.
and a second discharge passage having a flow area smaller than that of the first discharge passage, which is configured to control communication between the discharge passage of the low-speed hydraulic chamber and the discharge oil passage of the low-speed hydraulic chamber, and the switching valve has a first oil chamber that communicates with the high-speed hydraulic chamber and a second oil chamber that is supplied with hydraulic pressure when the throttle valve is fully open; communication between the discharge passage and the discharge oil passage, and when hydraulic pressure is supplied to at least one of the arm chambers, the second discharge passage and the discharge oil passage are made to communicate with each other. A shift control device for an automatic transmission characterized by: 2. After the shift valve is switched during gear shifting, when the throttle valve is not in a fully closed state, the low-speed hydraulic chamber is communicated only with the first discharge path, and the hydraulic pressure in the high-speed hydraulic chamber is transferred to the switching valve. After the oil pressure is supplied, the low speed hydraulic chamber is made to communicate with the second discharge path, and when the throttle valve is fully closed, the switching valve is connected to the low speed hydraulic chamber by the hydraulic pressure supplied to the second oil chamber. 2. A speed change control device for an automatic transmission according to claim 1, wherein said second discharge path and said second discharge path communicate with each other. 3. The speed change control device for an automatic transmission according to claim 1 or 2, wherein the first discharge path includes an orifice.