JPS6322360Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an automatic transmission for a vehicle having four forward gears.

Various hydraulic control devices have been proposed and put into practical use in order to prevent shift shocks in automatic transmissions for vehicles, but it has always been possible to achieve smooth shifts with fewer shift shocks under various vehicle operating conditions. In order to do this, many complicated control valves are required in the hydraulic control circuit that engages and releases the frictional engagement device, and even if the control valve has a spool valve structure, the structure of the control valve is complicated and many control valves are required. Even if the valve was installed in the hydraulic circuit, there was an unavoidable drawback that some shift shocks may occur depending on the operating condition due to the structure.

The present invention has been proposed in order to eliminate the above-mentioned drawbacks, and is provided with at least four friction elements operated by hydraulic pressure, and the first speed is changed to the second speed by the engagement of the first friction element. is the same first friction element and second friction element.
The third speed is caused by the engagement of the first friction element and any two of the third and fourth friction elements, and the fourth speed is caused by the engagement of the second friction element and the fourth friction element. A shift from the first speed to the second speed is achieved by the engagement of the second friction element, and a shift from the second speed to the third speed is achieved by the engagement of the second friction element. This is achieved by disengaging and engaging the third friction element, and after the third friction element is fully engaged, the fourth friction element is engaged, and the shift from the third gear to the fourth gear is achieved by the engagement of the first friction element in advance. This is achieved by releasing the third friction element and engaging the second friction element after the release, and shifting from fourth gear to third gear is achieved by releasing the second friction element and engaging the third friction element. the first friction element is engaged after the third friction element is fully engaged, and the third friction element is shifted from the third speed to the second speed after previously releasing the fourth friction element. an electro-hydraulic exchange device configured to achieve this by releasing the friction element and engaging the second friction element, and controlling the pressure reduction of only the oil pressure supplied to the second and third friction elements; and an electro-hydraulic exchange device that detects the driving state of the vehicle. a detection device;
an electronic control device that provides a control signal to the electro-hydraulic exchange device in accordance with the signal from the detection device;
The gist of the present invention is an automatic transmission for a vehicle, characterized in that it is configured to supply a low oil pressure depending on the driving state of the vehicle to the second and third friction elements for a short period of time during gear shifting.

According to the present invention, the operating state of the vehicle is determined within the electronic control device, and the electro-hydraulic exchange device is operated according to the operating state to smoothly engage or disengage the frictional engagement device during gear shifting. Since a low oil pressure suitable for the transmission is supplied to the frictional engagement device according to the operating condition, smooth shifting with less gear shifting shock can be achieved in all operating conditions.

Also, according to the present invention, between 1st speed and 2nd speed, 2nd speed
Only the second and third friction elements are involved in the occurrence of a shift shock when shifting between 1st and 3rd speeds, and between 3rd and 4th speeds. The advantage is that a multi-stage automatic transmission with fewer shift shocks can be obtained by a control device with a simple configuration in which the electronic control device controls the supplied hydraulic pressure to a low hydraulic pressure only for a short period of time during gear shifting.

Next, one embodiment of the present invention will be described in detail with reference to FIGS. 1 to 12.

In the power train diagram shown in FIG. 1, a crankshaft 2 of an engine 1 serving as a power source for the vehicle is directly connected to a pump 4 of a torque converter 3. The torque converter 3 includes a pump 4, a turbine 5, a stator 6, and a one-way clutch 7. The stator 6 is connected to a case 8 via the one-way clutch 7, and the one-way clutch 7 connects the stator 6 to the crankshaft 2. The structure allows rotation in one direction, but does not allow rotation in the opposite direction.
A direct coupling clutch 9 is provided between the crankshaft 2 and the turbine 5, and the clutch 9 engages with a predetermined slip ratio when engaged.

Therefore, the output of the engine 1 is the output of the direct coupling clutch 9.
Alternatively, the torque is transmitted to the turbine 5 via the torque converter 3.

The torque transmitted to the turbine 5 is transmitted by an input shaft 10 to a transmission gear train 100 disposed at the rear thereof that achieves four forward speeds and one reverse speed.

The transmission gear train 100 includes three sets of clutches 11, 1
2, 13, two sets of brakes 14, 15, one set of one-way clutch 16, and one set of Ravigneau type planetary gear set 17.

The planetary gear set 17 includes an annulus gear 18, a reverse sun gear 19, a forward sun gear 20, a long pinion 21, a short pinion 22, and a carrier 23.

The annulus gear 18 is fixed to the output shaft 24,
The reverse gear 19 is fixed to a kick-down drum 25, and the drum 25 is connected to the kick-down brake 1.
4 to the case 8, and is also integrated to the input shaft 10 via the front clutch 11,
On the other hand, the forward sun gear 20 is connected to the rear clutch 1.
A carrier 23, which is integrated with the input shaft 10 via the input shaft 2 and which holds the long pinion 21 and the short pinion 22, is fixed to the case 8 via the one-way clutch 16 and is connected to the transmission gear train 1.
It is integrated into the input shaft 10 via a 4-speed clutch 13 provided at the rear end of the 00, and is further fixed to the case 8 via a low reverse brake 15.

One-way clutch 16 is provided to prevent reverse rotation of carrier 23.

The three sets of clutches 11, 12, 13 and the two sets of brakes 14, 15 are hydraulic friction engagement devices, and the oil pressure supplied to each hydraulic piston that operates these friction engagement devices is supplied to an oil pump 26. occurs in

The output passing through the speed change gear train 100 is transmitted to the output shaft 24.
The transmission is transmitted from the transfer drive gear 27 fixed to the transfer idle gear 28 to the transfer driven gear 29, and is further integrated into the transfer shaft 30,
The signal is transmitted from the helical gear 31 to the differential gear 32 . Depending on the operation of the select lever on the driver's seat (not shown) and the auxiliary switch for selecting D ₄ and D ₃ (described later), and the driving state of the vehicle detected by various driving detection devices described later, each of the frictional engagement devices described above is controlled. Selective engagement occurs to achieve various gears.

Select patterns are P (parking), R (reverse), N
(neutral), D ₄ (4 forward automatic transmission), D ₃ (3 forward automatic transmission), 2 (2 forward automatic transmission), L (1st speed fixed)
The select levers are P, R, N,
It has six positions: D, 2, and L, and when the auxiliary switch is selected with the lever in the D position, D ₃ or D ₄ will be selected.

How each friction engagement device works when the select lever and auxiliary switch are placed in each position of the above select pattern is as shown in the operating element diagram in Figure 2. By selectively combining the devices, a gear ratio of four forward speeds and one reverse speed can be obtained.

In this figure, the O mark indicates a friction engagement device that is engaged by hydraulic operation, the ● mark indicates that the carrier 23 is stopped by the action of the one-way clutch 16, and the select lever and auxiliary switch position is D. ₄ , D ₃ , 2, 1st, 2nd, 3rd in the L column,
4th indicates the case of husband's 1st speed, 2nd speed, 3rd speed, and 4th speed. Next, the direct coupling clutch 9 will be explained with reference to FIG.

This direct coupling clutch 9 is a slip type clutch that transmits power while constantly slipping. When the clutch 9 is in operation, the power from the engine 1 is mainly transmitted to the input shaft 10 via the clutch 9, and some of the power is transmitted to the input shaft 10. is transmitted via the torque converter 3,
This reduces the slip of the torque converter 3 and improves fuel efficiency, and this slip also has the effect of alleviating the impact torque from the engine 1 (dashing effect).

The torque converter 3 and the direct coupling clutch 9 are integrally formed, and a drive plate 33 is fixed to the crankshaft 2, and the drive plate 33 is connected to the outer shell 34 of the pump 4 of the torque converter 3 and the friction plate 35 of the direct coupling clutch 9. The turbine 5 is spline-fitted to the input shaft 10 and rotates integrally with the input shaft 10, and is also connected to the piston 38 via a torsion spring 37 so as to rotate integrally with the input shaft 10. 3
8 is fitted to be slidable and rotatable in the axial direction with respect to the input shaft 10, and has a friction surface 39 that is disposed opposite to the plate 36 and comes into contact with the friction plate 35, and the piston 38 and the plate 36 A hydraulic chamber 41 is formed between the piston 38 and the outer peripheral surface of the outer shell 40 of the turbine 5, and a hydraulic chamber 42 is formed between the piston 38 and the outer peripheral surface of the outer shell 40 of the turbine 5.

Friction plate 35 and friction surface 39 of the direct coupling clutch 9
The coefficient of dynamic friction is set so that the rate of change due to speed difference is small.

A plurality of grooves are appropriately provided on the surface of the friction plate 35 along the radial direction, circumferential direction, or a combination of the two, and the friction plate 35 and the friction surface 39 are formed by oil passing through the grooves. Overheating is prevented.

Oil is supplied to the torque converter 3 and the direct coupling clutch 9 with oil pressure regulated by hydraulic control, which will be described later.

As shown by the arrow in FIG. 3, the oil is guided into the torque converter 3 through an oil passage 43 formed on the inner surface of a sleeve 43 fitted externally to the input shaft 10 of the pump 4, and is circulated, and is further introduced into a hydraulic chamber 42. It is then led to the hydraulic chamber 41 through the gap between the friction plate 35 and the friction surface 39 of the direct coupling clutch 9, and further discharged through the oil passage 45 bored in the input shaft 10, or , and are now being circulated in the opposite direction.

Next, hydraulic control and electronic control of the frictional engagement device will be explained with reference to FIG.

The hydraulic control device is connected to the oil filter 4 from the oil sump 46.
7. The oil discharged from the oil pump 26 through the oil passage 402 is transferred to the torque converter 3, the direct coupling clutch 9, the front clutch 11, the rear clutch 12,
In order to operate the hydraulic pistons of the kickdown brake 14, low reverse brake 15, and 4-speed clutch 13, the hydraulic pressure supplied to each hydraulic chamber is controlled according to the operating state, and is mainly controlled by the pressure regulating valve 50 and torque converter control valve. 70, direct coupling clutch control valve 9
0, pressure reducing valve 110, shift valve pressure reducing valve 130, manual valve 150, 1st speed - 2nd speed shift valve 170, 2nd speed -
3rd speed shift valve 190, 3rd speed-4th speed shift valve 21
The components include a 0- and 4-speed clutch control valve 230, a hydraulic pressure control valve 250 during gear shifting, an orifice control valve 270, and three solenoid valves 300, 310, and 320, and each element is connected by an oil path. . The solenoid valves 300, 310, and 320 have the same structure, and operate the orifices 301, 3, respectively, by electrical signals from the same electronic control device 290.
It is a duty control solenoid valve of the non-energized closed type that controls the opening and closing of 11 and 321, and solenoids 302, 312, and 322, and each orifice 301, 311, and 321 arranged in the solenoid.
Valve bodies 303, 313, and 323 that open and close the valve bodies, and springs 304, 31 that bias the valve bodies in the closing direction.
4 and 324.

The electronic control device 290 has a built-in gear shift detection device etc. that detects the start of gear shifting, detects the driving state of the vehicle, and operates the solenoid valves 300, 310, 320.
The valve is stopped and the single pulse current width of the 50 Hz pulse current supplied to the solenoid valve is controlled to change the valve opening time to control the oil pressure.The main input element is the engine 1 (not shown). An engine load detection device 330 that detects the throttle valve opening or intake manifold negative pressure, a rotation speed detection device 331 of the engine 1, a rotation speed detection device 332 of the kickdown drum 25 shown in FIG. 1, and a rotation speed detection device of the output shaft 24. A rotation speed detection device 333 of the transfer driven gear 29 provided for performing the above, an oil temperature detection device 334 that detects the lubricating oil temperature, a select lever selection position detection device 341, an auxiliary switch selection position detection device 342, etc. It is completed. Oil discharged from the oil pump 26 is guided through an oil passage 401 to a pressure regulating valve 50, a manual valve 150, a direct clutch control valve 90, and pressure reducing valves 110 and 130.

The pressure regulating valve 50 has a spool 53 and a spring 54 having pressure receiving surfaces 51 and 52, and a manual valve 150 on the pressure receiving surface 51 is selected at N, D ₄ , D ₃ , 2, and L positions by operating a select lever. At the same time, the oil pressure in the oil passage 401 is applied to the oil passage 4 through the manual valve 150.
03 through the orifice 404, and as a result, the oil pressure in the oil passage 401 is regulated to a constant pressure of 7 kg/cm ² . Then, the oil pressure in the oil passage 401 acts from the oil passage 405 through the orifice 406, and as a result, the oil pressure in the oil passage 401 is regulated to 17 kg/cm ² .

Note that the relief valve 40 provided in the oil passage 401
7 is a relief valve when high pressure oil is discharged from the oil pump 26.

The oil led to the pressure reducing valve 110 through the oil passage 401 is regulated to 2.3 kg/cm ² by the same valve 110 and is led to the oil passages 408 , 409 and 410 .

The pressure reducing valve 110 has a spool 111 and a spring 1.
12 and an adjustment screw 113, the spool 111
The pressure is regulated by the balance between the hydraulic pressure due to the area difference between the pressure receiving surfaces 114 and 115 formed opposite to each other and the spring 112, and the hydraulic pressure is adjusted to 2.3 kg/cm ² by the adjusting screw 113. are doing.

The pressure regulating oil guided to the oil passage 409 is through the orifice 4.
26 to the hydraulic control valve 250 and the orifice 321 of the solenoid valve 320.

The orifice 426, the hydraulic control valve 250, and the solenoid valve 320 constitute an electro-hydraulic converter 340 that generates control hydraulic pressure in the oil passage 422 according to the operating state during gear shifting by the operation of the valve 320.

The hydraulic control valve 250 has pressure receiving surfaces 251, 252, 2
53, has a spool 254 with a pressure receiving surface 25
1 and the hydraulic pressure due to the area difference between the pressure receiving surfaces 252 and 253.
22 is regulated to a predetermined pressure.

The control oil pressure led to the oil passage 422 controls the front clutch 11 and the kickdown brake 14.

The solenoid valve 320 is connected to an engine load detection device 330, a rotation speed detection device 333, and an oil temperature detection device 3.
The electronic control unit 290 detects the operating condition in response to the signal from the
The opening/closing time of the orifice 321 is controlled by changing the pulse width through duty control. The solenoid valve 320 controls the hydraulic pressure P ₁ acting on the pressure receiving surface 251 of the hydraulic control valve 250 by setting the orifice 426 to 0.8φ and the orifice 321 to 1.4φ, adjusting the pressure between 0.3 and 2.3 Kg/cm ^{2 .} be done. The relationship between the hydraulic pressure _P1 controlled by the hydraulic control valve 250 and the output hydraulic pressure _P2 generated in the oil passage 422 is as shown in FIG.

In addition, the start of operation and the operation period of the solenoid valve 320 are determined by the various detection devices 330, 333, and 33 described above.
4, a shift detection device built into the electronic control unit 290 that detects the start of a shift, an engagement timing detection device consisting of two rotational speed detection devices 332 and 333, and the like.

On the other hand, the pressure regulating oil guided to the oil passage 408 reaches the pressure reducing valve 130 and the orifice 311 of the solenoid valve 310 via the orifice 411.

The orifice 411, the pressure reducing valve 130, and the solenoid valve 310 control the control hydraulic pressure corresponding to the gear ratio according to the operating state by the operation of the valve 310.
occurs in

The pressure reducing valve 130 has pressure receiving surfaces 131, 132, 133.
It has a spool 134 and a spring 135 with hydraulic pressure acting on the pressure receiving surface 131 and the pressure receiving surface 1.
The oil pressure in the oil passage 412 is regulated to a predetermined pressure by the balance between the total force of the hydraulic pressure due to the area difference between the oil passage 32 and the pressure receiving surface 133 and the biasing force of the spring 135. The control oil pressure led to the oil passage 412 is the first speed -
2nd speed shift valve 170, 2nd speed-3rd speed shift valve 19
It controls the 0, 3rd and 4th speed shift valves 218 and the 4th speed clutch control valve 230.

The solenoid valve 310 mainly receives signals from the engine load detection device 330 and the rotation speed detection device 3.
The orifice 31 is detected by detecting the signal from the orifice 33 and changing the pulse width by controlling the duty at 50 Hz in the same way as the solenoid valve 320, according to the operating state set in advance in the electronic control unit 290.
Controls the opening/closing time of 1.

The control of the hydraulic pressure acting on the pressure receiving surface 131 of the pressure reducing valve 120 by the solenoid valve 310 is regulated in five stages.

Note that the orifice 41 installed in the oil passage 412
3 is provided to prevent the output oil pressure P ₃ of the oil passage 412 from pulsating due to the duty control of the solenoid valve 310.

The 1st speed-2nd speed shift valve 170 has a spool 171 and a spring ₁₇₂ , and the spool 17
1 is selectively switched between the left end position shown in FIG. 4 and the right end position (not shown).

Similarly, the 2nd-3rd speed shift valve 190, the 3rd-4th speed shift valve 210, and the 4th speed clutch control valve 230 each have spools 191, 211, 231 and springs 192, 212, 232, and the left end of each spool has a spring 192, 212, 232. Pressure receiving surfaces 193, 213, and 233 are provided, and each spool is selectively switched between a left end position shown in FIG. 3 and a right end position not shown. In this embodiment, the first speed-second speed shift valve 1
70 switches when a hydraulic pressure of 0.25 kg/cm ² acts on the pressure receiving surface 173, the 2nd-3rd speed shift valve 190 switches when a hydraulic pressure of 0.8 kg/cm ² acts on the pressure receiving surface 193, and the 4th speed clutch control valve 230 is the pressure receiving surface 233
Switching occurs when hydraulic pressure of 1.45Kg/ ^cm2 is applied, and 3rd gear -
The 4-speed shift valve 210 has a pressure of 2.2Kg/cm ² on the pressure receiving surface 213.
The springs 172, 192, 212, and 232 are set so as to switch when hydraulic pressure is applied.

In addition, the output oil pressure P ₃ by the solenoid valve 310
In order to switch and control these valves, the same output oil pressure P ₃ which switches in 5 stages of 0, 0.5, 1.1, 1.8, 2.6 Kg/cm ² according to the operating condition and each of the above valves 170, 190,
The relationship between the positions of the spools 210 and 230 and the gears is as shown in FIG.

Next, shift control based on selective engagement of each frictional engagement device will be explained.

When the manual valve 150 is switched from N to D, 7
Oil with hydraulic pressure 401 regulated to Kg/cm ² flows into oil path 414.
and 415.

The oil in the oil passage 415 flows through the orifice 41 arranged in parallel.
6. The oil passes through the 3rd-4th speed shift valve 210 via the check valve 417, and is further led from the oil passage 418 to the hydraulic chamber of the rear clutch 12 through the orifice 419 and the orifice control valve 270, and when the rear clutch 12 is engaged. 1st gear is achieved.

At this time, the accumulator 420, orifice 416, and check valve 4 installed in the oil passage 414
17 prevents a sudden rise in hydraulic pressure in the hydraulic chamber of the rear clutch 12, thereby preventing a shock.

When the accelerator is depressed, the electronic control device 29
A command to achieve 2nd speed is issued to the solenoid valve 310 from 0, the oil pressure P ₃ in the oil passage 412 is increased from 0 to 0.5Kg/cm ² , and the spool 171 of the 1st-2nd speed shift valve 170 is switched to the right end. .

Due to this switching, the oil in the oil passage 415 is transferred to the oil passage 421.
The oil is guided to the oil passage 422 through the oil pressure control valve 250 and supplied to the engagement side oil pressure chamber 423 of the kickdown brake 14, and the rod 424 is connected to the spring 4.
25 to the left to engage a brake band (not shown) with the kickdown drum 25, and second speed is achieved.

At this time, as described above, the hydraulic control valve 250 responds to the hydraulic control of the solenoid valve 320 to control the oil passage 42.
2 hydraulic pressure is reduced only during gear shifting to prevent gear shifting shock.

In this case, during power-on upshift, the output oil pressure _P2 from the oil pressure control valve 250 has oil pressure characteristics determined mainly by the throttle opening degree and vehicle speed, and in this embodiment, it has the characteristics shown in FIG. 7.

In other words, generally speaking, the greater the throttle opening during gear shifting, the greater the torque acting on the friction engagement device.
In addition, the smaller the vehicle speed, the greater the torque acting on the friction engagement device, so the output oil pressure _P2 is adjusted in proportion to the magnitude of this torque, so that the friction engagement device operates smoothly within a short time and without shock. It creates an engagement force that corresponds to the driving condition, thereby preventing gear shift shock and improving shift quality.

Further, the start of operation of the hydraulic control valve 250 is synchronized with the shift timing by the solenoid valve 310, and its operation period differs between two operating states: the above-mentioned power-on upshift and the engine brake upshift, which will be described later.

That is, during a power-on upshift in which acceleration is performed by gradually depressing the accelerator, the hydraulic control valve 250 is operated for a short period of time, for example, about one second, to prevent a neutral state from occurring.

An example of the temporal change in the output oil pressure P ₂ in this case is as shown by the solid line in FIG. 8, and the output oil pressure P ₂ may be controlled to be gradually increased as shown by the broken line.

When the engine brake is upshifted by suddenly releasing the accelerator, the rotation of the kick-down drum 25 is reversed with respect to the input shaft 10, as shown in Fig. 9, and the speed gradually decreases until it comes to a standstill. becomes.

This stop state or just before the stop is detected by the rotation speed detection device 332, and at the time of this detection, the hydraulic control valve 2
Stop the operation of 50 and set down brake 14.
Engagement is performed in a timely manner. Note that during engine braking, the output oil pressure P ₂ controlled by the oil pressure control valve 250 is maintained at a low oil pressure of 1 kg/cm ² or less in order to obtain a light initial engagement state in the frictional engagement device.

When the hydraulic pressure P ₃ is increased to 1.1 kg/cm ² in order to achieve the third speed according to a command from the electronic control unit 290, the spool 191 of the second speed-third speed shift valve 190 is switched to the right end. At this time, the oil passage 421 is communicated with the oil passage 428, and the oil passage 422 is communicated with the oil passage 429.

Oil passage 428 leads to four-speed clutch control valve 230 via orifice 430 and to orifice control valve 270.

The orifice control valve 270 has a spool 271 and a spring 272, and controls opening and closing of the bypass passage 431 of the orifice 419 in the oil passage 418 by hydraulic pressure acting on two pressure receiving surfaces 273 and 274 of the spool 271.

The oil passage 429 passes through the 3rd-4th speed shift valve 210 and the oil passage 432 to the release side hydraulic chamber 433 of the kickdown brake 14 and the orifice control valve 270.
The switching valve 43
4 to the hydraulic chamber of the front clutch 11.

Due to the structure in which this oil passage 432 is communicated with the release side hydraulic chamber 433 of the kick-down brake 14 and the hydraulic chamber of the front clutch 11, engagement and release of the two are performed with overlap.

During the shift from the second speed to the third speed, the hydraulic pressure control valve 250 operates in exactly the same manner as during the shift from the first speed to the second speed, and the hydraulic pressure supplied to the oil passage 422 is maintained low for a short time.

An orifice 444 is interposed in the oil passage 432, and by the action of the orifice 444, the oil pressure in the oil pressure chamber 433 and the oil pressure chamber of the front clutch 11 is maintained at the same low oil pressure while the oil pressure control valve 250 is operating. In parallel with the release of the kick-down brake 14, the front clutch 11 is engaged, and then the hydraulic pressure control valve 250 stops operating, causing the hydraulic pressure to decrease to 7.
When the pressure is increased to Kg/cm ² , engagement of the front clutch 11 is completed and third gear is achieved.

In this case, if the upshift is in the engine braking state, the input shaft 1
0 and the rotational speed of the kick-down drum 25 approach and match the rotational speed of the output shaft 24, so the rotational speed detection device 32 detects this matched state or just before that.
2,333, and upon this detection, the operation of the hydraulic control valve 250 is stopped.

When the third speed is achieved, the planetary gear set 17 is integrated, but at this moment the solenoid valve 310 is controlled to increase the oil pressure _P3 to 1.8Kg/ ^cm2 , and as a result, the
The spool 231 of the speed clutch control valve 230 is switched to the right end.

By this switching, communication between the oil passage 428 and the oil passage 445 and between the oil passage 412 and the oil passage 446 is achieved, the 4-speed clutch 13 is supplied with oil pressure and held in the engaged state, and the oil passage 446 is connected to the oil pressure P ₃ to 3rd gear - 4
It is supplied to the pressure receiving surface 213 of the speed shift valve 210.

3 by switching the 4-speed clutch control valve 230.
Hydraulic pressure is supplied to the pressure receiving surface 213 of the 3rd to 4th speed shift valve 210 when the 4th speed clutch control valve 230 is fixed at the left end position shown in FIG. 3 by the stay. spool 2
This is to prevent the danger of shifting to the right when the gear 11 moves to the right, causing the gear to shift to neutral when it should be in 4th gear.

With the auxiliary switch set to D ₄ , when the hydraulic pressure P ₃ reaches 2.6 kg/cm ² to achieve 4th gear according to a command from the electronic control unit 290, the spool 211 of the 3rd-4th gear shift valve 210 shifts to the right end. The oil in the oil passages 418 and 432 is drained.

At this time, the oil in the hydraulic chamber of the rear clutch 12 is pumped through the check valve 44 installed in parallel with the orifice 419.
7, the rear clutch 12 is immediately released, and the front clutch 11 is also released after the oil in the hydraulic chamber is drained, but this is similar to the shift from 1st to 2nd gear or from 2nd to 3rd gear. The hydraulic pressure control valve 250 is activated to reduce the hydraulic pressure in the oil passage 422 for a short period of time during gear shifting, so that the engagement hydraulic pressure acting on the hydraulic pressure 423 of the kick-down brake 14 is also low and smooth engagement is performed. Then, when the engagement oil pressure rises to 7 kg/cm ² , engagement is achieved and 4th gear is completed.

In this case, if the engine is braking, the first
As shown in FIG. 1, the rotational speed of the kickdown drum 25 decreases and reaches a stopped state, so the rotational speed detection device 332 detects this instant or immediately before the rotational speed and stops the operation of the hydraulic control valve 250.

Next, to explain the downshift, the switching of the hydraulic pressure operating system is the reverse of the above-mentioned upshift. First, in order to shift from 4th gear to 3rd gear by a command from the electronic control unit 290, the hydraulic pressure P ₃ changes to 1.8 kg/ cm ² , the spool 2 of the 3rd-4th speed shift valve 210
11 is switched to the left end, and hydraulic pressure is supplied to the oil passages 418 and 432. At this time, the orifice control valve 270
The bypass oil passage 431 is closed by the hydraulic pressure acting on the pressure receiving surface 273, and oil is smoothly supplied to the hydraulic chamber 433 of the kick-down brake 14 and the hydraulic chamber of the front clutch 11 via the orifice 444. The hydraulic pressure chamber of the rear clutch 12 is gradually supplied via an orifice 419 with a sufficient delay compared to the front clutch 11. At this time, the kick-down brake 14 is immediately released, but even during this deceleration shift, the short-time oil pressure control valve 250 is operated, and the oil passages 418, 4
The hydraulic pressure supplied to the input shaft 10 is maintained at a low pressure, and during a power-off downshift, the operation of the hydraulic pressure control valve 250 is stopped after a set time of approximately 1 second has elapsed, and during a power-on downshift, the hydraulic pressure supplied to the input shaft 10 is maintained at a low pressure. and the kickdown drum 25 is the output shaft 2.
2 because the speed is increased to match the rotation speed of 4.
Integration of the planetary gear set 17 is detected by the two rotation speed detection devices 332 and 333, and the integrated three
The operation of the hydraulic control valve 250 is stopped at the moment when the gear train is in a high drive ratio state, and the oil passages 418, 432 are stopped.
Since the hydraulic pressure supplied to is increased to 7Kg/cm ² ,
The front clutch 11 is completely engaged a little after the release of the kick-down brake 14, and synchronization between the carrier 23 and the input shaft 10 is substantially completed. At this time, the hydraulic pressure increased to 7 kg/cm ² in the oil passage 432 is sent to the orifice control valve 27 as a synchronization detection signal.
It acts on the pressure receiving surface 273 of 0.

When the hydraulic pressure acting on the pressure-receiving surface 273 of the orifice control valve 270 increases, the spool 271 moves to the left end position as shown in the figure, opening the previously closed bypass oil passage 431, and the hydraulic pressure is no longer supplied to the hydraulic chamber of the rear clutch 12. This occurs immediately through the bypass oil passage 431, and engagement of the rear clutch 12 is achieved. This is done in order to prevent a shift shock caused by engagement from the rear clutch 12, which has a large torque capacity.

When shifting from 3rd gear to 2nd gear, oil pressure P ₃ is 0.5
The pressure is regulated to Kg/ ^cm2 , and each spool 23 of the 4th speed clutch control valve 230 and the 2nd speed-3rd speed shift valve 190
1,191 moves to the left end, the engagement of the 4th speed clutch 13 is immediately released, and the disengagement of the front clutch 11 and the engagement of the kickdown brake 14 are performed by hydraulic pressure in the same way as the shift from 4th to 3rd speed. control valve 2
50, the shift is performed gradually and the second gear is smoothly achieved.

When shifting from 2nd gear to 1st gear, oil pressure _P3 is 0.
, the spool 1 of the 1st-2nd speed shift valve 170
71 moves to the left end, kicking down brake 14
The oil in the hydraulic chamber is discharged, the brake 14 is disengaged, and the first speed is achieved.

When D ₃ or 2 position is selected by operating the select lever and auxiliary switch, manual valve 1
The oil passage is not switched at all by 50, but its position is detected by the select lever selection position detection device 341 and the auxiliary switch selection position detection device 342, and a signal is given to the electronic control device 290.
The solenoid valve 310 is controlled so that shifting to 4th speed or 3rd speed or higher is not performed.

When the manual valve 150 is selected to the L position, the position is detected by the selection lever selection position detection device 341, and if the vehicle speed is above a predetermined value such as 40 km/h at the initial stage of selection, the vehicle is held at 2nd gear, and thereafter the vehicle speed is increased. When the value is below a predetermined value, the first speed is fixed by controlling the solenoid valve 310, and the oil passage 414 and the oil passage 448 are communicated with each other, and the oil is supplied to the orifice 449 and the check valve 45 which are installed in parallel with the oil passage 448.
0 to the 1st-2nd speed shift valve 170, and is further led to the oil passage 451, the switching valve 452, and the oil passage 45.
3 to the hydraulic chamber of the low reverse brake 15, and the first speed is achieved.

In addition, the spool 17 of the 1st speed-2nd speed shift valve 70
1 is provided with an orifice 454, an orifice 449, and a check valve 45.
Due to the action of 0, the hydraulic pressure supplied at the time of switching is maintained at a low pressure and a shock is prevented.

When the manual valve 150 is selected to the R position, the oil passage 4
01 is communicated with an oil passage 455, and the oil passage 455 is connected to an orifice 456 and a check valve 45 arranged in parallel.
7 to the switching valve 452, and the oil is delayed by the orifice 456 before passing through the switching valve 45.
2. The oil passage 453 leads to the low reverse brake 15, while the oil passage 455 is connected to the switching valve 434 via an oil passage 458, and the front clutch 1
Oil is also supplied to the hydraulic chamber of clutch 11,
Retraction is achieved by engagement of 15.

By the way, the oil led to the torque converter control valve 70 from the oil passage 459 through the pressure regulating valve 50 is
The pressure is regulated to 2.5 Kg/cm ² and the oil passes through the oil passage 460 to the direct clutch control valve 90 .

Further, the oil in the oil passage 460 is supplied to the lubrication system on the engine 1 side of the transmission from an oil passage 467 and an oil cooler 462 via an orifice 461, and is supplied to the lubrication system on the side opposite to the engine 1 via an orifice 463. Supplied.

The oil whose pressure is regulated to 2.3 kg/cm ² by the pressure reducing valve 110 and led to the oil passage 401 reaches the orifice 301 which is controlled to open and close by the solenoid 300 via the orifice 464.

The direct clutch control valve 90 has a spool 91 and a spring 92, and is operated by a solenoid 300.
The control hydraulic pressure regulated between 0.3 and 2.3 kg/cm ² acts on the pressure receiving surface 93 at one end of the spool 91, and the pressure receiving surface 9
The flow direction of the oil supplied to the torque converter 3 and the direct coupling clutch 9 and its oil pressure are controlled in accordance with the balance between the hydraulic pressure acting on the torque converter 3 and the biasing force of the spring 92.

The oil passage 44 following the torque converter 3 is an oil passage 46
5 and connected to the direct coupling clutch 9, the oil passage 45 is connected to the oil passage 466, and the direct coupling clutch control valve 90 is connected to the oil passage 466.
By switching control, the oil passage 465 is selectively communicated with the supply oil passage 401 or the discharge oil passage 467 via an orifice 468 that reduces oil pressure pulsation.
66 is selectively communicated with the supply oil passage 460 or the discharge oil passage 467.

When an engagement command for the direct coupling clutch 9 is given to the solenoid 300 by the electronic control unit 290, the oil pressure regulated by the direct coupling clutch control valve 90 is transferred from the oil passage 401 to the oil passage 465 as shown by the solid line arrow in FIG. The direct coupling clutch 9 is supplied to the hydraulic chamber 4
The piston 38 is pushed leftward by the hydraulic pressure acting on the piston 2 and is engaged with a predetermined amount of slip.

If the hydraulic pressure acting on the piston 38 is controlled by a computer to provide a slip amount that is slightly below the range of speed fluctuations of the crankshaft 2 caused by the fluctuating torque of the engine 1, most of the fluctuating torque of the crankshaft 2 can be transmitted. This results in highly efficient power transmission and improved fuel efficiency.

By the way, when starting or suddenly accelerating, it is necessary to remove the direct coupling clutch 9 in order to utilize the characteristics of the feeling torque converter 3. At this time, the computer 290 stops energizing the solenoid valve 290, and the direct coupling clutch control valve 90 switch to the fourth
Oil flows in the opposite direction to the above, indicated by the dashed arrow in the figure. In other words, the low oil pressure of 2.5Kg/cm ² caused by the torque converter control valve 110 is transferred from the oil path 460 to 4.
66, the piston 38 of the direct coupling clutch 9 moves to the right by the hydraulic pressure acting on the hydraulic chamber 41, and its engagement is released.

According to the embodiment described above, shifting between 2nd and 3rd gears, and between 3rd and 4th gears is achieved by coupling and releasing the front clutch 11 and the kickdown brake 14, and shifting between 1st and 2nd gears is achieved by coupling and releasing the front clutch 11 and the kickdown brake 14. This is achieved by connecting or releasing the downbrake 14, and by installing the hydraulic control valve 250 in the oil passage that supplies control hydraulic pressure only to these two friction engagement devices, the hydraulic control by the valve 250 can be applied to other friction devices. Unnecessary slips are prevented without affecting the engagement device.

Further, according to the above embodiment, when shifting between 1st, 2nd, 3rd, and 4th speeds, the torque acting on the friction engagement device is relatively small for only about 1 second during power-on upshifts and power-on downshifts. A low hydraulic pressure regulated according to the operating condition is applied to the frictional engagement device to be engaged, and the engagement is completed without shock with the optimum engagement force, and it also acts on the frictional engagement device. During upshifts during engine braking and downshifts when power is on, the front clutch 1 is about to engage.
1 or a pair of friction elements of the kick-down brake 14, that is, a pair of friction elements provided on the input shaft 11 and the kick-down drum 25 in the case of the front clutch 11, and a pair of friction elements provided in the case 8 and the kick-down drum 25 in the case of the kick-down brake 14. Shift shock is prevented by increasing the hydraulic pressure at the moment or just before the relative rotation of the gears stops, thereby completing engagement from a light initial engagement state.

In addition, the solenoid valve 320 controls the single pulse current width of the 50 Hz pulse current to control the orifice 321.
This is a duty control solenoid valve that is closed when energized and changes the opening time of the solenoid valve 320.Moreover, the hydraulic pressure received by the solenoid valve 320 is controlled within a low hydraulic pressure range (0.3 to 2.3 Kg/
cm ² ), the desired control oil pressure can be easily obtained with high accuracy by changing the current width using the electronic control device 290.
0 or when the solenoid valve 320 becomes inactive due to a failure of the solenoid valve 310, the orifice 321 is closed and the oil passage 422 is filled with the normal 7.
Kg/ ^cm2 hydraulic pressure is supplied to ensure minimum operation. Furthermore, according to the above embodiment, since the shift shock during normal gear shifting is extremely reduced, a very large torque is generated when starting or suddenly accelerating. It becomes possible to keep the direct coupling clutch 9 in the operating state even when changing gears, except in the driving state. Note that during this gear shift, the transmitted torque increases and the slip amount of the direct coupling clutch 9 increases compared to the normal case.
The transmission torque handled by the direct coupling clutch 9 and the torque converter 3 is about half and half.

[Brief explanation of the drawing]

Fig. 1 is a power train diagram of an automatic transmission for a vehicle showing an embodiment of the present invention, and Fig. 2 shows the engagement state of each frictional engagement device in the above automatic transmission in relation to the select lever position. Working element diagram,
FIG. 3 is a sectional view of the torque converter and direct coupling clutch of the same embodiment, FIG. 4 is a system diagram showing the hydraulic control device of the automatic transmission, and FIG. 5 is a diagram of the electro-hydraulic converter adopted in the above embodiment. A hydraulic diagram showing the control characteristics; FIG. 6 is a diagram showing the relationship between the shift valve switching control device of the above embodiment, the output oil pressure _P3 , and the gear stage;
Fig. 7 is a hydraulic characteristic diagram of output oil pressure P ₂ , Fig. 8 is a time change diagram of output oil pressure P ₂ , and Figs. 9, 10, 11, and 12 are diagrams showing speed changes during gear shifting. It is. 1...Engine, 10...Input shaft, 11,1
2, 13...Clutch, 14, 15...Brake, 17...Ravigniot type planetary gear set, 24...Output shaft, 50...Pressure regulating valve, 110...Pressure reducing valve, 15
0...Manual valve, 170...1st-2nd speed shift valve,
190... 2nd speed-3rd speed shift valve, 210... 3rd speed - 4th speed shift valve, 230... 4th speed clutch control valve, 250... Hydraulic control valve, 270... Orifice control valve, 290... Electronic control device, 300,3
10, 320... Solenoid valve, 330... Engine load detection device, 331, 332, 333...
Rotation speed detection device, 334...Oil temperature detection device, 34
1... Select lever selection position detection device, 34
2... Auxiliary switch selection position detection device, 340
...Electro-hydraulic conversion device.

Claims (1)

[Utility Model Claims] (1) A gear mechanism including a set of planetary gears and at least four friction elements operated by hydraulic pressure.
The first gear is engaged by the engagement of a first friction element, and the second gear is engaged by the engagement of the first friction element and a second friction element.
The third speed is achieved by engaging any two of the first friction element and the third and fourth friction elements, and the fourth speed is achieved by engaging the second friction element and the fourth friction element. A shift from the first speed to the second speed is achieved by engaging the second friction element, and a shift from the second speed to the third speed is achieved by releasing the second friction element and engaging the third friction element.
After the first friction element is completely engaged, the fourth friction element is engaged, and the shift from the third speed to the fourth speed is performed in advance according to the first friction element.
This is achieved by releasing the third friction element and engaging the second friction element after releasing the fourth friction element.
(2) An automatic transmission for a vehicle, characterized in that a shift from first gear to third gear is achieved by releasing the second friction element and engaging the third friction element, the first friction element is engaged after the third friction element is fully engaged, and a shift from third gear to second gear is achieved by releasing the third friction element and engaging the second friction element after the fourth friction element has been released in advance, the automatic transmission for a vehicle further comprising an electro-hydraulic exchange device which reduces and controls the hydraulic pressure supplied to the second and third friction elements only, a detection device which detects the operating state of the vehicle, and an electronic control device which provides the electro-hydraulic exchange device with a control signal corresponding to a signal from the detection device, and is configured to supply a low hydraulic pressure corresponding to the operating state of the vehicle to the second and third friction elements for a short period of time during a shift.
2. An automatic transmission for a vehicle according to claim 1, which is a registered utility model, characterized in that it comprises a hydraulic control valve interposed in the middle of a common oil passage which supplies pressure oil from a hydraulic source to friction elements, and a duty control solenoid valve of a non-energized closed type which receives a control signal from said electronic control device and adjusts a control oil pressure for controlling said hydraulic control valve.