JPS6211229B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a direct control device for a fluid transmission device such as a torque converter or a fluid coupling in an automatic transmission for a vehicle.

It is located between an input member and an output member of a torque converter as a fluid transmission device, and is connected to the input member and the output member during operation.
A direct coupling mechanism that directly couples the output members without allowing any slippage between them is known and is in public use, but when this direct coupling mechanism is operated at low vehicle speeds,
Since vibration is likely to occur and the torque amplification function of the torque converter cannot be obtained, power performance also deteriorates. Therefore, in reality, the direct coupling mechanism is controlled so that it operates above a certain vehicle speed. Direct coupling mechanisms that divide power between the torque converter and the mechanical system at a fixed ratio are also known and in use, but these are generally expensive, and the slip loss of the torque converter remains unbearable. Therefore, it is not a perfect measure to reduce fuel consumption.

Therefore, the present applicant developed a direct coupling mechanism consisting of a taper and a roller, which has a power splitting function and whose split ratio can be variably controlled from 0 to 100%, and whose thrust force is variable. We have previously proposed a method for controlling the division ratio. This direct coupling mechanism is configured to operate based on the differential pressure between the controlled operating pressure and the internal pressure of the torque converter. There is a system that increases the capacity of the direct coupling mechanism during high-speed running by controlling the internal pressure in relation to each other and further lowering the internal pressure on the high-speed side. However, if the output of the engine is improved or the number of gears of the auxiliary transmission increases, sufficient power performance can be obtained without relying as much on the torque amplification function of the torque converter. The purpose of power splitting is primarily to prevent vibration from worsening.

Therefore, in areas where direct connection of a torque converter is likely to cause vibration and deterioration of marketability, such as when a vehicle is running at a constant medium speed in an urban area, power is split and the accelerator pedal is pressed to accelerate from that area. Even when starting operation, it is desirable to perform power split control using the throttle opening as a parameter so that the power flowing to the torque converter side does not increase too much.

The present invention was made in view of such circumstances, and by controlling the internal pressure of the fluid transmission device so that it is inversely proportional to the engine output, the power division of the fluid transmission device is controlled, thereby reducing vibration and power performance. An object of the present invention is to provide a direct-coupling control device for a fluid transmission device in a vehicle automatic transmission that prevents deterioration.

According to the present invention, in the middle of the outlet oil passage connecting the outlet of the fluid transmission device to the oil tank, the valve body is biased toward the opening side by the internal pressure of the fluid transmission device, and is biased toward the closing side by the biasing member. A pressure holding valve is provided to open the valve body, and a pipe line for introducing fluid pressure representative of the engine output is connected to a pressure acting chamber provided to open the valve body.

Hereinafter, an embodiment of the present invention will be explained with reference to the drawings. First, in FIG. axis 1
Torque converter T as a fluid transmission device,
The signal is transmitted to the drive wheels W, W' through the auxiliary transmission M and the differential Df in order to drive them.

The torque converter T includes a pump wheel 2 directly connected to a crankshaft 1, a turbine wheel 3 connected to an input shaft 5 of an auxiliary transmission M, and a stator shaft 4a supported on the input shaft 5 so as to be relatively rotatable. It is composed of a stator wheel 4 connected via a one-way clutch 7. The torque transmitted from the crankshaft 1 to the pump impeller 2 is hydrodynamically transmitted to the turbine impeller 3, and during this time, when the torque is amplified,
As is known, the stator wheel 4 bears the reaction force.

A pump drive gear 8 for driving the hydraulic pump P shown in FIG. 2 is provided at the right end of the pump impeller 2, and a stator arm 4b for controlling the regulator valve Vr shown in FIG. 2 is fixed at the right end of the stator shaft 4a. will be established.

A roller-type direct coupling clutch Cd is provided between the pump impeller 2 and the turbine impeller 3 as a direct coupling mechanism capable of mechanically coupling them. To explain this in detail with reference to FIGS. 2 and 3, an annular drive member 10 having a drive conical surface 9 on the inner circumference is spline-fitted to the inner peripheral wall 2a of the pump impeller 2. Further, a driven member 12 having a driven conical surface 11 facing parallel to the driving conical surface 9 on its outer periphery is spline-fitted to the inner circumferential wall 3a of the turbine impeller 3 so as to be slidable in the axial direction. A piston 13 is integrally formed at one end of this driven member 12, and this piston 13 is slidably engaged with a hydraulic cylinder 14 provided on the inner circumferential wall 3a of the turbine wheel 3.
4 and the internal pressure of the torque converter T are simultaneously received on both left and right end surfaces.

A cylindrical clutch roller 15 is interposed between the driving and driven conical surfaces 9 and 11, and as shown in FIG.
is a virtual conical surface 1 passing through the center between both conical surfaces 9 and 11
It is held by an annular retainer 16 so as to be inclined at a constant angle θ with respect to the generatrix g of c (FIG. 2).

Therefore, when a hydraulic pressure higher than the internal pressure of the torque converter T is introduced into the hydraulic cylinder 14 at a stage when the torque amplifying function of the torque converter T is no longer necessary, the piston 13, that is, the driven member 12, moves toward the drive member 10. being pushed. As a result, the clutch roller 15 is pressed against both conical surfaces 9 and 11.
At this time, when the drive member 10 is rotated in the X direction in FIG. 3 with respect to the driven member 12 by the output torque of the engine E, the clutch roller 15 rotates. Since o is inclined as described above, its rotation gives relative axial displacement to both members 10 and 12, which causes them to approach each other. As a result, the clutch roller 15 bites between both the conical surfaces 9 and 11, and between the two members 10 and 12, that is, the pump impeller 2
and the turbine wheel 3. Even when the direct coupling clutch Cd is operated in this way, the output torque of the engine E exceeds the coupling force and the output torque of the two-winged vehicle 2,
3, the clutch roller 15 slips on each conical surface 9, 11, and the above torque is divided into two, with some torque being applied to the direct coupling clutch.
The remaining torque is transmitted mechanically via Cd, and the remaining torque is transmitted hydrodynamically via both wing wheels 2 and 3, so that the ratio of the former torque to the latter torque is variable, changing depending on the degree of slippage of the clutch roller 15. A power split system is formed.

If a reverse load is applied to the torque converter T while the direct coupling clutch Cd is in operation, the driven member 12
Since the rotational speed of the driving member 10 becomes larger than that of the driving member 10, the driving member 10 relatively rotates in the Y direction with respect to the driven member 12, and the clutch roller 15 rotates in the opposite direction from the previous rotation. This applies a relative axial displacement to both members 10, 12 that causes them to move apart from each other. As a result, the clutch roller 15 is released from being wedged between the conical surfaces 9 and 11, and enters an idling state. The transfer of the reverse load from the turbine wheel 3 to the pump wheel 2 therefore takes place only hydrodynamically.

When the hydraulic pressure of the hydraulic cylinder 14 is released, the piston 13 receives the internal pressure of the torque converter T and retreats to its original position, so that the direct coupling clutch Cd becomes inactive.

Referring again to FIG. 1, a first gear train is connected between the mutually parallel input and output shafts 5 and 6 of the auxiliary transmission M.
G ₁ , second speed gear train G ₂ , third speed gear train G ₃ , fourth speed gear train G ₄ , and reverse gear train Gr are provided in parallel.

The first speed gear train _G1 includes a drive gear 17 connected to the input shaft 5 via a first speed clutch _C1 , and a drive gear 17 that meshes with the gear 17 and can be connected to the output shaft 6 via a one-way clutch Co. It consists of a driven gear 18. The second speed gear train G ₂ consists of a driving gear 19 connectable to the input shaft 5 via a second speed clutch C ₂ and a driven gear 20 fixed to the output shaft 6 and meshing with the gear 19. The third speed gear train G ₃ includes a drive gear 21 fixed to the input shaft 5 and a third speed clutch C ₃ to the output shaft 6.
The driven gear 22 is connected to the gear 21 via a driven gear 22 and can mesh with the gear 21. In addition, the fourth gear train G ₄ is
It consists of a driving gear 23 connected to the input shaft 5 via a fourth speed clutch _C4 , and a driven gear 24 connected to the output shaft 6 via a switching clutch Cs and meshing with said gear 23. Furthermore, the reverse gear train Gr is
A drive gear 25, which is provided integrally with the drive gear 23 of the fourth speed gear train _G4 , and a driven gear 27, which is connected to the output shaft 6 via the switching clutch Cs, mesh with both gears 25 and 27. It consists of an idle gear 26. The switching clutch Cs is connected to the driven gear 2.
4, 27, and selectively connects the driven gears 24, 27 to the output shaft 6 by shifting the selector sleeve S of the clutch Cs to the forward position on the left or the reverse position on the right in the figure. can do. One-way clutch Co only transmits drive torque from engine E, and does not transmit torque in the opposite direction.

Therefore, when the selector sleeve S is held in the forward position as shown in the figure, the first gear clutch is
If only C ₁ is connected, the drive gear 17 will be connected to the input shaft 5.
A first speed gear train G ₁ is established, and torque is transmitted from the input shaft 5 to the output shaft 6 via this gear train G ₁ . Next, if the second speed clutch _C2 is connected while the first speed clutch _C1 is connected, the drive gear 19 is connected to the input shaft 5 and the second speed gear train is connected.
_G2 is established, and torque is transmitted from the input shaft 5 to the output shaft 6 via this gear train _G2 . At this time, the first gear clutch _C1 is also engaged, but due to the action of the one-way clutch Co, it is not in first gear but in second gear, which is the same as in third and fourth gears. The same is true. When the second speed clutch _C2 is released and the third speed clutch _C3 is connected, the driven gear 22 is connected to the output shaft 6 to establish the third speed gear train _G3 , and the third speed clutch _C3 is connected. When the fourth speed clutch C4 is released and the fourth speed clutch _C4 is connected, the drive gear 23 is connected to the input shaft 5 and the fourth speed gear train _G4 is established. Furthermore, move the selector sleeve S of the switching clutch Cs to the right, and
If only speed clutch C ₄ is connected, drive gear 25
is connected to the input shaft 5, and the driven gear 27 is connected to the output shaft 6.
A reverse gear train Gr is established by being connected to the gear train Gr, and reverse torque is transmitted from the input shaft 5 to the output shaft 6 via this gear train Gr.

The torque transmitted to the output shaft 6 is transmitted from the output gear 28 provided at the end of the shaft 6 to the large diameter gear D _G of the differential device Df.

In FIG. 2, a hydraulic pump P sucks up oil from an oil tank R and pumps it into a hydraulic oil passage 29. After this pressure oil is regulated to a predetermined pressure by the regulator valve Vr, the manual valve Vm as a manual switching valve
sent to. This oil pressure is called line pressure Pl.

The regulator valve Vr has a pressure regulating spring 30 and a spring receiver 31 that supports the outer end of the spring receiver 31, and the spring receiver 31 can be moved left and right to adjust the set load of the pressure regulating spring 30. . This spring receiver 3
The stator arm 4b is in contact with the outer surface of the stator wheel 4 so as to apply a reaction force acting on the stator wheel 4, that is, a stator reaction force, and the spring receiver 31 is provided with a stator arm 4b for supporting the stator reaction force. Spring 3
2 is connected. Therefore, if the stator reaction force increases, the stator spring 32 will be compressed, and accordingly the spring receiver 31 will move to the left, increasing the set load of the pressure regulating spring 30, and as a result, the hydraulic oil passage 29 will be compressed. Line pressure Pl is increased.

A part of the pressure oil whose pressure is regulated by the regulator valve Vr is guided into the torque converter T through an inlet oil passage 34 having a throttle 33, and pressurizes the inside thereof to prevent cavitation. A pressure holding valve 36 is provided in the outlet oil passage 35 of the torque converter T, and the oil that has passed through the pressure holding valve 36 returns to the oil tank R via an oil cooler 56.

The surplus of pressure oil discharged from the hydraulic pump P is guided to the lubricating oil path 38 from the regulator valve Vr and sent to the various lubricating parts. is the lubricating oil path 38
connected to.

The manual valve Vm is linked to a gear shift lever (not shown) and is set to a parking position Pk, a reverse position Re, a neutral position N, a 4-speed forward automatic transmission position D ₄ , and a 3-speed forward automatic transmission position D ₃ excluding 4th speed. and a second speed holding position, which can be freely switched between six positions. Pressure oil sent to this manual valve Vm is supplied to the clutch when this valve Vm is in the neutral position N shown in the figure.
It is not sent to any of C ₁ , C ₂ , C ₃ , C ₄ and other various hydraulic operating parts. Therefore, all four clutches C ₁ , C ₂ , C ₃ , C ₄ are disengaged, and the torque of the engine E is not transmitted to the drive wheels W, W'.

When the manual valve Vm moves one step to the left from the illustrated neutral position N and is shifted to the forward four-speed automatic transmission position _D4 , the hydraulic oil passage 29 from the hydraulic pump P communicates with the oil passages 43, 118, Also, the first gear clutch
Hydraulic oil passage 41 leading to hydraulic cylinder 40a of _C1
a communicates with the oil passage 29 via the oil passage 118. Further, the oil passage 47 communicates with the oil passage 80, and the oil passage 81
communicates with an oil passage 82 leading to the hydraulic cylinder 40b of the fourth speed clutch _C4 . Furthermore, oil passage 113a,
113 is isolated from discharge oil passage 114 and oil passage 112, and oil passage 115 continues to be connected to discharge port 116.
is connected to. The oil passage 43 communicates with the spring chamber 42 of the servo motor Sm for shifting the selector sleeve S (see FIG. 1), so that the piston 44 of the servo motor Sm remains in the leftward movement position shown in the figure. The selector sleeve S is held in the forward position shown in FIG. 1 via the shift fork 45. As a result, the driven gear 24 is connected to the output shaft 6, the driven gear 27 can freely rotate around the output shaft 6, and the reverse gear train Gr is placed in an inactive state.

When the manual valve Vm is shifted to the 3rd forward automatic transmission position D ₃ , it is the same as the 4th forward automatic transmission position D ₄ except that the oil passage 80 is isolated from the oil passage 47 . Further, although the oil passage 81 and the oil passage 82 appear to be separated, these oil passages 81 and 82 communicate with each other via an annular groove 102 provided in the spool valve body 101 of the manual valve Vm.

An input oil passage 46 connected to an input port of a governor valve Vg branches from a hydraulic oil passage 29 connected to the hydraulic pump P, and an oil passage 47 extends from an output port of the valve Vg. The governor valve Vg is a well-known one and is a differential gear
It is rotated around its own rotation axis 49 by the gear 48 that meshes with the large diameter gear D _G of Df. As a result, 3
Centrifugal force acts on the three weights 51a, 51b, and 51c to bias them in the valve opening direction, and the oil pressure in the oil passage 47 biases them toward the closing side, which biases them toward the opening side to achieve desired characteristics. A pair of springs 50a and 50b are provided. According to the governor valve Vg, the oil pressure proportional to the vehicle speed, that is, the governor valve Pg can be outputted to the oil passage 47.

When the manual valve Vm is in the 4th forward automatic transmission position D ₄ and the 3rd forward automatic transmission position D ₃ , an oil passage 53 branches off from the oil passage 43 on which the hydraulic pressure from the hydraulic pump P acts, and this oil The passage 53 is connected to the first throttle valve Vt ₁ via the modulator valve 54 and to the second throttle valve Vt ₂ via the oil passage 105 .

The modulator valve 54 is a pressure reducing valve that is biased toward the closing side by a spring force and closed by the modulator pressure of the output port 54a, and defines the upper limit value of the input pressure to the first throttle valve _Vt1 .

The first throttle valve Vt ₁ is of a known type, and includes a spool valve body 55, a control spring 58 that presses the valve body 55 to the left, and a return spring 5 that presses the valve body 55 to the right.
7. Control piston 59 that supports the outer end of control spring 58, control cam 60 that rotates in conjunction with the increase in opening of the throttle valve of engine E and moves control piston 59 to the left, and adjusts the set load of return spring 57. It has an adjustment bolt 61 etc. that can be adjusted. When the control piston 59 moves to the left, the displacement is transmitted to the spool valve body 55 via the control spring 58 and pushes it to the left. Push the spool valve body 55 back to the right.
As a result, the first throttle valve Vt ₁ outputs a hydraulic pressure proportional to the throttle valve opening of the engine E, that is, the first throttle pressure Pt ₁ to the oil passage 52. Note that the counterclockwise rotation of the control cam 60 continuously restricts the communication between the drain oil passage 117 and the oil tank R.

The second throttle valve Vt ₂ is inserted between the oil passage 105 and the oil passage 106, and is connected to the spool valve body 107.
and a control spring 10 that presses the valve body 107 to the left.
8, a control piston 109 that supports the outer end of the control spring 108, and a control cam 110 that rotates in conjunction with an increase in the throttle opening of the engine E and moves the control piston 109 to the left. control piston 1
09 moves to the left, the displacement is transmitted to the spool valve body 107 via the control spring 108, and the spool valve body 107 moves to the left. Along with this leftward movement, oil passage 1
The hydraulic pressure output at 06 acts on the left shoulder portion 107a of the spool valve body 107 so as to push the spool valve body 107 back to the right. By such operation, the second
The throttle valve Vt ₂ applies a second throttle pressure Pt ₂ proportional to the throttle opening of the engine E to the oil passage 106.
Output to.

From the first throttle valve Vt ₁ to the first throttle pressure Pt ₁
The oil passage 52 that guides the 1-2 shift valves V ₁ and 2-3
The oil passage 47' is connected to the first pilot hydraulic chambers 62a, 62b, and 62c of the shift valves _V2 and 3-4 shift valves _V3, respectively, and branches from the oil passage 47 that leads the governor pressure Pg from the governor valve Vg. 2 shift valve
It communicates with the second pilot hydraulic chambers 63a, 63b of _V1 and 2-3 shift valve _V2 . Further, when the manual valve Vm is in the 4th forward automatic gear shift position _D4 , the oil passage 80, which can communicate with the oil passage 47 via the manual valve Vm, is connected to the second pilot hydraulic chamber 63c of the 3-4 shift valve _V3 . communicated. As a result, the spool valve bodies 64a, 6 of each shift valve V ₁ , V ₂ , V ₃
4b and 64c receive governor pressure Pg and first throttle pressure _Pt1 at both ends and are operated as follows.

That is, the spool valve body 64a of the 1-2 shift valve _V1 initially remains at the rightward movement position shown in the figure by the force of the spring 66, and the oil passage 118 is cut off from the oil passage 70. At this time, the oil passage 118 is in communication with the hydraulic oil passage 41a, so the first speed clutch _C1 is engaged under pressure. Therefore, the first speed gear train _G1 is established.

Next, the vehicle speed increases and the governor pressure Pg increases,
When the left power of the spool valve body 64a due to this governor pressure Pg overcomes the right power of the valve body 64a due to the first throttle pressure Pt ₁ and the spring 66, the valve body 64a
In the click motion mechanism 67 provided at the right end of the valve body 64, a click ball 68 moving together with the valve body 64a passes over a fixed positioning protrusion 69, and the valve body 64a is switched to the left movement position, and the oil passage 118 is moved to the oil passage 70. communicate with. Also, the oil passage 70 is the drain oil passage 1
26. In this state, the 2-3 shift valve
When V ₂ is in the position shown, oil passage 70 is connected to oil passage 81.
The oil passage 81 further communicates with an oil passage 82. Since this oil passage 82 communicates with the hydraulic oil passage 41b which communicates with the hydraulic cylinder 40b of the second speed clutch _C2 , the second speed clutch _C2 is engaged under pressure and the second speed gear train _G2 is established.

When the vehicle speed further increases, the 2-3 shift valve V ₂
, the spool valve body 64b moves to the left, and the oil passage 8
1 is communicated with the drain oil passage 119, the oil passage 70 is communicated with the oil passage 83, and the oil passage 83 is further isolated from the drain oil passage 120. As a result, the second speed clutch _C2 is disengaged. On the other hand, if the 3-4 shift valve _V3 is in the illustrated position, the oil passage 83 communicates with the hydraulic oil passage 41c. This hydraulic oil passage 41c communicates with the hydraulic cylinder 40c of the third speed clutch _C3 , so that the third speed clutch _C3 is pressurized into engagement and the third speed gear train _G3 is established.

Next, when the vehicle speed further increases while the manual valve Vm is in the forward 4-speed automatic gear shift position _D4 ,
3-4 Shift valve V ₃ second pilot hydraulic chamber 63
Since the governor pressure Pg is acting on C through the oil passage 80, the spool valve body 64c moves to the left, the hydraulic oil passage 41c is communicated with the drain oil passage 122, and the third speed clutch _C3 is engaged. is canceled. At the same time, the oil passage 113 is isolated from the drain oil passage 117 and communicated with the oil passage 83. The oil passage 113 communicates with the hydraulic oil passage 41d via the manual valve Vm, and the hydraulic oil passage 41d communicates with the hydraulic cylinder 40d of the _fourth speed clutch _C4. Pressurized engagement establishes the fourth speed gear train _G4 .

Manual valve Vm is in forward 3-speed automatic gear shift position D ₃
, the oil passage 80 is isolated from the oil passage 47 by the manual valve Vm, so no force is applied to move the spool valve body 64c to the left, and therefore the fourth speed clutch _C4 is not engaged. 4th gear train _G4 is not established.

In order to relieve the shock during gear shifting, accumulators 72, 73, and 74 are provided, and the drain oil path 119 is provided with a 1-2 orifice control valve 124, and the drain oil path 122 is provided with a 2-3 orifice control valve 125. is provided.

During deceleration, the spool valve bodies 64a, 64b, and 64c move to the right in the order of 3-4 shift valve _V3 , 2-3 shift valve _V2, and 1-2 shift valve _V1 , and return to 1st speed when stopped. . Manual valve Vm is the second
When in the high speed holding position, the oil passage 118 is isolated from the oil passage 29 and communicates with the oil tank R, and the oil passage 8
2 communicates with the oil passage 43 via the annular groove 102, and only the second speed clutch _C2 is engaged under pressure to maintain the second speed. Also, the manual valve Vm is in the retreat position Re.
, the oil passage 43 communicates with the oil tank R, the oil passage 115 is isolated from the discharge oil passage 116 and communicates with the oil passage 29, and the spring chamber 4 of the servo motor Sm
2 is pressurized. Therefore, the piston 44 moves to the right, moves the selector sleeve S (see FIG. 1) to the right, and establishes the reverse gear train Gr. At the same time, the oil pressure in the oil passage 112 increases, which causes the manual valve to
Since the oil is guided to the hydraulic oil passage 41d via Vm, the fourth speed clutch _C4 is pressurized and engaged, and the vehicle moves backward.

Now, the configuration of the operating pressure control means Dc that controls the operation of the direct coupling clutch Cd will be explained with reference to FIG.
0,160,170. These three valves 150, 160, 170 only need to be connected in series, and their connection order does not matter.

The valve 150 is a lock-up release valve for releasing the lock-up during gear shifting, and includes a spool valve body 151 that moves between a first switching position on the right and a second switching position on the left, and a spool valve body 151 that moves between a first switching position on the right and a second switching position on the left. The first pilot hydraulic chamber 152 facing the left end surface and the valve body 151
The second pilot hydraulic chamber 153a facing the right end surface of
, the third pilot hydraulic chamber 153b facing the stepped portion 151a facing the right side of the valve body 151;
and a spring 154 that presses it to the right side. The first pilot hydraulic chamber 152 communicates with the oil tank R,
The second pilot hydraulic chamber 153a has an oil passage 86 branched from the hydraulic oil passage 41d to the fourth speed clutch _C4 .
An oil passage 87 branched from the hydraulic oil passage 41b to the second speed clutch _C2 is communicated with the third pilot hydraulic chamber 153b. The pressure receiving area facing the second pilot hydraulic chamber 153a of the valve body 151 and the third
The pressure receiving area facing the pilot hydraulic chamber 153b is made approximately equal. Land 1 is provided on the outer periphery of the valve body 151.
Two annular grooves 157, 1 symmetrically sandwiching 56.
58 is provided, and when the valve body 151 is in the first switching position as shown, the regulator valve
An oil passage 130 that guides pressure oil whose pressure is regulated by Vr communicates with an output oil passage 161 to the valve 160. This state does not change even when the valve body 151 is in the second switching position on the left, but when the valve body 151 is in the middle of moving between the first switching position and the second switching position, the output oil passage 161 is It is temporarily blocked from the passage 130 and communicated with the oil passage 159 leading to the oil tank R.

The valve 160 is connected to the output oil passage 161 and the oil passage 16.
A spool valve body 164, which is a modulated valve provided between the valve body 164 and the first pilot hydraulic chamber 165, which moves between a closed position on the left and an open position on the right; and valve body 16
A second pilot hydraulic chamber 166 facing the right shoulder portion 164a provided at the right end of the pilot hydraulic chamber 166, a plunger 168 that enters the first pilot hydraulic chamber 165 and comes into contact with the valve body 164, and the other facing the left end surface of the plunger 168. 3rd pilot hydraulic chamber 1 as a pressure chamber
69 and a spring 167 housed in the third pilot hydraulic chamber 169. The first pilot hydraulic chamber 165 is communicated with an oil passage 155 that guides the governor pressure Pg from the governor valve Vg, so that the governor pressure Pg is introduced into the first pilot hydraulic chamber 165. In addition, the third pilot hydraulic chamber 169 has a second
An oil passage 131 branched from the oil passage 106 that introduces the second throttle pressure Pt ₂ from the throttle valve Vt ₂ is communicated with the third pilot hydraulic chamber 169, so that the second throttle pressure Pt ₂ acts on the third pilot hydraulic chamber 169. Furthermore, the second pilot hydraulic chamber 166 is communicated with an oil passage 171 that guides the operating oil pressure to the direct coupling clutch Cd via an oil passage 133 having a throttle 132. Therefore, the second
The operating hydraulic pressure of the direct coupling clutch Cd is introduced into the pilot hydraulic chamber 166.

Note that the second pilot hydraulic chamber 166 has an oil passage 1.
63 may be communicated. Also spring 1
Reference numeral 67 is for correcting the engagement force of the direct coupling clutch Cd, and may be provided as necessary. Also, when the engagement force is too strong, it is provided to bias the spool valve body 164 toward the opening side. Sometimes.

In this modulated valve 160, the spool valve body 164 opens in proportion to the throttle opening, that is, the second throttle pressure _Pt2 . Also the second
When the throttle pressure _Pt2 is lower than the governor pressure Pg, the plunger 168 separates from the spool valve body 164, and the spool valve body 164 adjusts to the second throttle pressure.
Not affected by Pt ₂ .

The valve 170 is connected to the oil passage 163 and a direct coupling clutch.
A spool valve body 172 is provided between an oil passage 171 communicating with the hydraulic cylinder 14 of the Cd and moves between a closed position on the right and an open position on the left, and a 1 Pilot hydraulic chamber 17
3, a second pilot hydraulic chamber 174 facing the right end surface of the valve body 172, and a spring 175 that biases the valve body 172 toward the closing side. First pilot hydraulic chamber 17
3 communicates with the oil tank R, and the second pilot hydraulic chamber 174 is connected to the oil passage 106 via an oil passage 178. In this valve 170, the pressure in the second pilot hydraulic chamber 174, that is, the second throttle pressure
When Pt ₂ is smaller than the spring force of the spring 175, it closes as shown in the figure, and the hydraulic pressure of the hydraulic cylinder 14 in the direct coupling clutch Cd is connected to the oil passage 171 and the release port 1.
It is released to the oil tank R via 76. Also the second
When the throttle pressure Pt ₂ overcomes the spring force of the spring 175, the valve body 172 moves to the left, the input oil passage 163 communicates with the oil passage 171, and the direct coupling clutch Cd operates. In this manner, the valve 170 is configured to operate the direct coupling clutch Cd when the throttle opening is at the idle position.
It functions to release the engaged state of the lock-up, that is, release the lock-up.

Further, the pressure holding valve 36 provided in the outlet oil passage 35 connecting the torque converter T and the oil tank R has its valve body 36a biased in the valve closing direction by a spring 37 as a biasing member, and the outlet oil Valve body 36a on the upstream side of passage 35, that is, the internal pressure of torque converter T.
is biased in the valve opening direction. Moreover, the valve body 36
A plunger 140 that can come into contact with the upstream end (upper end in FIG. 2) of the valve body 36a is arranged to press the valve body 36a in the valve opening direction. Pressure action chamber 1 facing the end
41 is communicated with an oil passage 142 branched from an oil passage 171 for guiding hydraulic pressure to the direct coupling clutch Cd.

Next, to explain the operation of this embodiment, in the direct coupling clutch Cd, the engagement force is determined by the differential pressure between the working oil pressure from the oil passage 171 and the internal pressure of the torque converter T. It is desirable to reduce the internal pressure of the torque converter T during driving. In order to meet this demand, when the vehicle speed increases, the plunger 140
6 is opened to lower the internal pressure of the torque converter T. In other words, when the vehicle speed becomes high enough, oil path 1
71 increases, the valve body 36a of the pressure holding valve 37 is pushed down by the plunger 140 to open the valve, the internal pressure of the torque converter T decreases, and the engagement force of the direct coupling clutch Cd is further strengthened. In this state, the amount of heat generated inside the torque converter T is extremely small, and there is less need for cooling with the oil cooler 56, and when the valve body 36a of the pressure holding valve 36 is pushed down further, most of the oil from the torque converter T is removed. The oil is directly dumped into the oil tank R via the discharge oil path 144. In this state, if the throttle pedal is returned to the idle position or a gear change is performed, the engagement state of the direct coupling clutch Cd must be released. This engagement state is released by pushing back the piston 13 using the internal pressure of the torque converter T. Therefore, in order to improve the responsiveness of this release operation, if the internal pressure of the torque converter T remains low, an inconvenience will occur. However, as the oil pressure in the oil passage 171 decreases, the plunger 14 moves toward the valve body 36a of the pressure holding valve 36.
Since the pressing force caused by 0 is released, the internal pressure of the torque converter T increases, and the engagement state is reliably released. Note that the valve body 36a and the plunger 140
Since it is separate from the oil passage 17, up to a certain vehicle speed,
1 cannot overcome the pressure at the upper part of the valve body 36a,
The internal pressure of the torque converter T is kept at a high predetermined value.

Such a pressure holding valve 36 and plunger 140
Fig. 4 shows the characteristics of the internal pressure of the torque converter T due to the action of . In FIG. 4, the two-dot chain line indicates the working oil pressure Pw of the oil passage 171 when the throttle opening is at the idle position.
The dashed line indicates the governor pressure Pg, and the solid line indicates the internal pressure P _T of the torque converter T.

When the throttle opening is at the idle position,
When the vehicle speed reaches U ₀ , the upper part of the plunger 140,
When the lower pressure becomes equal and exceeds U ₀ , the plunger 140 starts pushing the valve body 36a of the pressure holding valve 36,
The oil pressure above the valve body 36a, that is, the internal pressure P _T of the torque converter T begins to decrease. This state continues until the vehicle speed reaches _U1 , after which the internal pressure _PT becomes constant. Also, depending on the throttle opening, the internal pressure P
_T changes as shown by the broken line, and at full throttle, the vehicle speed at which the internal pressure P _T starts to decrease is from U ₀ .
Move to U ₀ ′.

In another embodiment of the invention, plunger 140
Throttle pressure Pt ₁ or
Pt ₂ may be applied; in this case, the internal pressure P _T of the torque converter T is constant with respect to the vehicle speed, and is inversely proportional only to the throttle opening. The degree of influence of the internal pressure P _T on the throttle opening can be adjusted simply by changing the diameter of the plunger 140, which is easy to handle in practical design. Further, as the throttle opening degree increases, the pressure drop created by the pressure holding valve 36 becomes smaller, so the recirculation flow rate of the torque converter T increases and the cooling performance improves.

The present invention can also be implemented in connection with an automatic transmission that uses a fluid coupling instead of the torque converter T described above.

As described above, according to the present invention, in the middle of the outlet oil passage connecting the outlet of the fluid transmission device to the oil tank, the valve body is biased toward the opening side by the internal pressure of the fluid transmission device, and a biasing member is provided. A pressure holding valve is provided that is biased toward the closing side, and a pipe line that guides fluid pressure representative of the engine output is connected to a pressure acting chamber that is provided to operate the valve body toward the opening side. Therefore, the internal pressure of the fluid transmission device is controlled to decrease in accordance with an increase in engine output, and the power division of the fluid transmission device is controlled in accordance with the engine output, thereby preventing vibrations and deterioration of power performance. Moreover, as the engine output increases, the amount of heat generated within the fluid transmission system increases, but by reducing the pressure drop at the pressure holding valve and increasing the oil return flow rate of the fluid transmission system, cooling performance is improved. can do.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic diagram of an automatic transmission with four forward speeds and one reverse speed to which the present invention is applied, FIG. 2 is a hydraulic control circuit diagram thereof, and FIG. 3 is a diagram of an automatic transmission with four forward speeds and one reverse speed. is an exploded view of the main parts of the direct coupling clutch in Figure 2, and Figure 4.
The figure is an internal pressure characteristic diagram of the torque converter. 35... Outlet oil path, 36... Pressure holding valve, 36a...
... Valve body, 37 ... Spring as biasing member, 140
... Plunger, 141 ... Pressure action chamber, Cd...
...Direct coupling clutch as a direct coupling mechanism, T...Fluid torque converter as a fluid transmission device, R...Oil tank.

Claims (1)

[Claims] 1 A fluid transmission device having an input member and an output member; and a direct coupling mechanism capable of mechanically directly connecting the input and output members of the fluid transmission device with an engagement force determined by a function of the working pressure and the pressure difference between the internal pressure of the fluid transmission device. In a direct-coupled control device for a fluid transmission device in a vehicle automatic transmission including; At the same time, a pressure holding valve is provided which is biased toward the closing side by a biasing member, and a pressure acting chamber provided to operate the valve body toward the opening side receives fluid pressure representing the engine output. 1. A direct-coupled control device for a fluid transmission device in an automatic transmission for a vehicle, characterized in that a conduit is connected thereto.