KR920006025B1 - Hydraulic control system for vehicle automatic transmission - Google Patents

Abstract

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Description

Hydraulic control of automatic transmission for vehicles

1 is a power system diagram of an automatic transmission for a vehicle to which an embodiment of the present invention is applied.

2 is a hydraulic circuit diagram showing a configuration of one embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

28: third friction element 30: fourth friction element

44: first friction element 54: second friction element

86: Pump

400A: first solenoid valve (first shift device)

400B: second solenoid valve (second shift device)

400C: third solenoid valve (fourth shift device)

400D: fourth solenoid valve (third shift device)

614 and 618: pressure receiving surface (first detection means)

626, 630, 710, 714: pressure receiving surface (second detection means)

632, 728: pressure receiving surface (third detection means)

722, 726: pressure receiving surface (fourth detection means)

600: first emergency safety valve (first switching valve)

636: spool (first switching means)

700: second emergency safety valve (second switching valve)

732: spool (second switching means)

The present invention relates to an improvement of an oil pressure control device of an automatic transmission for a vehicle.

The first, second, third, and fourth friction elements and the hydraulic source and the first friction element are provided in a flow path communicating with the first friction element to switch the supply and discharge of hydraulic pressure according to the driving state of the vehicle. A first shift device, a second shift device installed in a flow path communicating the hydraulic source and the second friction element, and switching the supply and discharge of hydraulic pressure to the second friction element according to a driving state of the vehicle; A third shift device installed in a flow path communicating the circle with the third friction element, and switching the supply and discharge of hydraulic pressure to the third friction element according to the driving state of the vehicle; and communicating the hydraulic source and the fourth friction element. It is provided in the flow path to the fourth friction element having a fourth shifting device for switching the supply and discharge of hydraulic pressure in accordance with the driving state of the vehicle, by selectively fitting two of the first to fourth friction elements Side An automatic transmission for a vehicle that can achieve fast speed is known from US Pat. No. 3,754,822.

This publication is configured to switch each friction element by on / off operation of a solenoid valve in which the supply and discharge of hydraulic pressure is connected to the spool valve of each shift device, and the solenoid valve malfunctions or the solenoid valve is replaced. Because of the failure of the controlling electronic control unit, friction elements other than a predetermined combination are simultaneously engaged, causing a contradiction in the torque transmission path of the automatic transmission gear train, which may cause the I / O shaft to lock or the transmission to be damaged. And a relay valve are provided in each flow path connecting each shift device.

For example, when the second friction element 54 and the second pinion gear 58 are engaged to achieve the first speed shift stage, the second relay valve, the third relay valve, and the fourth relay valve actuate hydraulic pressure. The hydraulic pressure supplied from the circle to the friction elements other than the second friction element 54 and the second pinion element 58 is blocked in front of the shifting device, and the hydraulic pressure of the friction element is discharged.

Therefore, what is described in the above publication is that the hydraulic pressure is not simultaneously supplied to two friction elements that are coupled at different gear stages at the same time, and the transmission is not damaged or locked.

However, in the above configuration, in order to achieve the above object, a relay valve must be provided for each flow path that communicates between the hydraulic source and each shift device, so that the cost is increased due to the increase in the number of parts and the number of parts in the hydraulic circuit. There is a disadvantage of causing an increase in the probability of occurrence of defects in the hydraulic circuits.

The present invention has been made in view of the above, and the first and second friction elements coupled to different gears, the main flow paths (88, 316) connected to the oil pump 86, and the main flow path respectively First and second solenoid valves 400A and 400B connected to the oil pump, flow paths 410 and 638 communicating the first friction element 44 and the first solenoid valve 400A, and the first In the hydraulic control apparatus of an automatic transmission for a vehicle having flow paths (416, 640) communicating two friction elements (54) and the second solenoid valve (400B), the hydraulic control device is formed between the flow paths (410, 638). A first emergency safety valve (600) having a supply position for supplying hydraulic pressure to the first friction element connected and a discharge position for discharging the hydraulic pressure from the first friction element, wherein the first emergency valve is provided The spool 636 for switching between position and discharge position And a pressure receiving surface 606 for pressing the spool to the supply position shaft, the pressure receiving surface 614 receiving the hydraulic pressure supplied to the first friction element to press the spool in the direction of the hydraulic discharge position. 618 and a pressure receiving surface (626, 630) for receiving the hydraulic pressure supplied to the second friction element to press the spool in the direction of the hydraulic discharge position is formed a hydraulic control device for a vehicle automatic transmission The point is to.

According to the configuration of the present invention, the hydraulic pressure is delivered to the first flow path and the second flow path at the same time due to a failure or malfunction of the first shift device or the second shift device, and when the hydraulic pressure reaches a predetermined value or more, the hydraulic pressure is placed in the first flow path. The switching valve is switched to the discharge position for discharging the hydraulic pressure of the first friction element, and it is necessary to provide a switching valve in each flow path by a structure that prevents the first friction element and the second friction element from being coupled at the same time. It can be achieved by increasing the minimum number of parts without the need to increase the cost and increase the defect occurrence rate in hydraulic circuits such as valve sticks, and can also simplify the hydraulic circuit.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2.

FIG. 1 is a skeleton diagram showing a gear shift of an automatic transmission that can achieve four forward and one reverse gear stages, wherein the drive shaft 10 directly connected to the crankshaft of the engine (not shown) is input to the torque converter 12. It is connected to the pump 16 of the torque converter 12 via the casing 14, the stator 18 of the torque converter 12 is connected to the transmission casing 22 via a one-way friction element 20. have.

In addition, the turbine 24 of the torque converter 12 passes through the input shaft 26 to form a third friction element 28 as a third coupling element, a fourth friction element 30 as a fourth coupling element and a fifth friction element. Connected to (32). The output side of the third friction element 28 is connected to the first carrier 38 of the first simple planetary gear device 36 (hereinafter referred to simply as the first gear device 36), and the first carrier ( 38 is the second carrier 42 of the second simple planetary gear device 40 (hereinafter referred to simply as the second gear device 40) which rotates integrally with the carrier 38 via the intermediate shaft 34 and It is connected to each of the first friction elements 44 as first coupling elements for stopping the rotation of the first intermediate shaft 34. The output side of the fourth friction element 30 is connected to the first sun gear 46 of the first gear device 36, and the output side of the fifth friction element 32 is via the second intermediate shaft 48. A first gear connected to the first ring gear 50 of the first gear device 36 and the second sun gear 52 of the second gear device 40 to stop the rotation of the second intermediate shaft 48; It is connected to the second friction element 54 as a two engagement element.

The first gear device 36 supports the first sun gear 46, the first pinion gear 56 meshing with the sun gear 46, and the pinion gear 56 freely while being rotatably supported. And a first ring gear 50 engaged with the rotatable first carrier 38 and the first pinion gear 56, and the second gear device 40 further comprises the second sun gear 52. ), The second pinion gear 58 meshing with the sun gear 52, the second carrier 42 and the second pinion gear rotatable themselves while supporting the pinion gear 58 freely. It consists of the 2nd ring gear 60 matched with 58). The second ring gear 60 is connected to the output gear 64 via a hollow output shaft 62 through which the first intermediate shaft 34 is inserted.

The output gear 64 is engaged with the driven gear 68 provided at the right end of the intermediate transmission shaft 66 disposed substantially parallel to the pressure shaft 26 via an idler 70, and the intermediate transmission shaft The left end of the 66 is connected to the final reduction gear 76 connected to the drive axle 74 via the differential gear device 72.

Further, as is apparent from FIG. 1, the transmission casing 22 includes each power transmission element from the torque converter 12 to the output gear 64, the intermediate transmission shaft 66, the differential gear device 72, and the like. It is formed to.

Each of the clutches and brakes is provided with a coupling piston device, a servo device, or the like, and is engaged and released while hydraulic pressure is supplied and discharged. The hydraulic pressure is selectively supplied to the respective clutches and brakes by the control device shown in FIG. 2, and the shift stage of the forward four-speed reverse one-stage is achieved by the operation combination of the respective clutches and the brakes.

The first table shows the relationship between the operation of each clutch and brake and the shift stage situation. In this table, the symbol "0" indicates engagement of the clutch or brake, and the symbol "-" indicates their release. .

TABLE 1

In the above configuration, when the first friction element 44 and the fourth friction element 30 are combined, the first carrier 38 and the third carrier 42 are fixed to form a reaction force element, and from the drive shaft 10 The driving force of the torque converter 12, the input shaft 26, the fourth friction element 30, the first sun gear 46, the first pinion gear 56, the first ring gear 50, the second aspect It is transmitted to the output shaft 62 via the gear 52, the second pinion gear 58, the second ring gear 60, and furthermore, the output gear 64, the intermediate transmission shaft 66, and the final reduction gear 76. Is transmitted to the drive axle 74 to achieve the first speed as evident from the first table.

Next, by releasing the friction element 44 and engaging the friction element 54 while maintaining the engagement state of the fourth friction element 30, the first ring gear 50 and the second sun gear 52 The rotation is stopped to become a reaction force element, and the driving force is output via the first sun gear 46, the first carrier 38, the second carrier 42, the second ring gear 60, and the output shaft 62. 64), a second velocity is achieved.

Next, by releasing the second friction element 54 and engaging the third friction element 28 while keeping the fourth friction element 30 engaged, the first sun gear 46 and the first carrier ( As the 38 is integrally rotated, the entire first gear device 36 is integrally rotated. Accordingly, the second sun gear 52 and the second carrier 42 are integrally rotated so that the entire second gear device 40 is also integrally rotated so that the input shaft 26 and the output gear 64 are rotated at the same rotational speed. A so-called direct third speed is achieved.

Furthermore, when the fourth friction element 30 is released while the third friction element 28 is engaged and the second friction element 54 is engaged, the driving force is reduced by the second sun gear 52 becoming the reaction force element. It is transmitted to the second carrier 42 via the first intermediate shaft 34, and outputs via the output shaft 62 as the second pinion gear 58 rotates while rotating around the outer circumference of the second sun gear 52. A third fourth speed is achieved, which is transmitted to the gear 64 and in which the rotation of the output gear 64 is faster than the rotation of the input shaft 26.

Next, when the third friction element 28 and the second friction element 54 are released and the fifth friction element 32 and the first friction element 44 are coupled, the second carrier 42 reacts with the reaction force. Element, the driving force is transmitted to the output gear 64 via the second intermediate shaft 48, the second sun gear 52, the second pinion gear 58, the second ring gear 60, and the output shaft 62. Transmission, the shift stage of reverse is achieved.

Next, in the gear transmission shown in FIG. 1, the configuration and operation of the hydraulic control device for achieving each speed change stage shown in the first table will be described.

The hydraulic control device shown in FIG. 2 is sucked from the oil pan 80 to the oil pump 86 via the filter 82 and the flow path 84 and discharged from the pump 86 to the flow path 88. Is supplied to the torque converter 12 while simultaneously engaging and releasing the respective friction elements 28, 30, 32 and the friction elements 44, 54 of the gear transmission shown in FIG. And selectively supplying and discharging according to the driving state of the vehicle by the friction element, mainly the pressure control valve 100, the torque converter control valve 200, the manual valve 300, and the first solenoid valve as the first shift device ( 400A), the second solenoid valve 400B as the second shift device, the third solenoid valve 400C as the fourth shift device, the fourth solenoid valve 400D as the third shift device, the flow pressure switching valve 500, First emergency safety valve 600 as first switching means, second as second switching means And a phase and a safety valve 700 as a component, the elements are connected by a flow passage.

The pressure regulating valve 100 adjusts the hydraulic pressure of the oil passage 88 to a desired value corresponding to the gear shift stage. The pressure regulating valve 100 has a land 106 having a pressure receiving surface 102 and a pressure receiving surface 104. Land 112 having a pressure receiving surface 108 and a pressure receiving surface 110 opposite the surface 104, a pressure receiving surface 114 and a pressure receiving surface 116 opposite the pressure receiving surface 110. Land 118 having a pressure, a pressure receiving surface 120 opposing the pressure receiving surface 116 and a land 124 having a pressure receiving surface 122, a pressure substantially opposite the pressure receiving surface 122. A spool 138 having a land 130 having a receiving surface 126 and a pressure receiving surface 128, and a land 136 having a pressure receiving surface 132 opposite the pressure receiving surface 128, and A spring 140 for contacting the land 136 to press the spool 138 in the right direction in the second direction, and the pressure receiving surface 108 has a hydraulic pressure area larger than that of the pressure receiving surface 104. And The pressure receiving surface 114 has a hydraulic pressure area larger than that of the pressure receiving surface 110, and the pressure receiving surface 120 has a hydraulic pressure area larger than the pressure receiving surface 116, respectively. The 122 and the pressure receiving surface 126, the pressure receiving surface 128, and the pressure receiving surface 132 each have the same hydraulic pressure area. In addition, the pressure receiving surface 102 has a flow passage 144 provided with an orifice 142, and the flow passage 88 has a flow passage 148 provided with an orifice 146 between the pressure receiving surfaces 104, 108. A flow path 152 provided with an orifice 150 is provided between the pressure receiving surfaces 110 and 114, and a flow path 156 provided with an orifice 154 is provided between the lands 130 and 136 between the pressure receiving surfaces 116 and 120. The flow path 88 via the flow path 158 and the flow path 164 communicated with the orifice 162 downstream of the flow path 160 communicate with each other, and the flow path 166 is connected between the land 130 and the land 124. It communicates with the flow path 84 via (circle).

The torque recirculator control valve 200 has a land 206 having the pressure receiving surfaces 202, 204, and a pressure receiving surface opposite the pressure demand surface 204 and having the same hydraulic area as the pressure receiving surface 204. A spool 214 having a land 212 having a 208 formed thereon, and a spring 216 that abuts the land 212 and presses the spool 214 in the right direction in the second direction, and the pressure regulating valve The hydraulic pressure of the oil passage 88 pressure-adjusted at 100 is applied to the pressure receiving surface 202 via the oil passage 160, the oil passage 168, and the oil passage 172 provided with the orifice 170 to press the pressure of the spring 216. The hydraulic pressure of the oil passage 168 is regulated to a predetermined pressure by equilibrium with the oil, and is supplied to the torque empty vent 12 through the oil passage 168. In addition, the oil discharged from the torque converter 12 is supplied to each lubrication portion of the transmission via the flow path 174. The manual valve 300 has a spool 302 which can be selected in three positions of R, NP, and D. The spool 302 sets lands 304, 306, 308, 310 and the spools in a desired position. It is disposed in the interior of the car for the purpose, the position P4, which is normally used during parking, the R position for reverse, the N position for stopping, the D4 position which enables shifting between the forward gears of the first to fourth speeds, D3 position where shifting is possible between the first and third shifting stages, D2 position where shifting to the third or more shifting speed is prohibited, and L position where shifting to the second or more shifting speed is prohibited. Is provided with a connection that is mechanically or electrically connected to a conventionally known selection lever not shown. When the selection lever is operated to select any one of D4, D3, D2, or L, the spool 302 is moved to the D position to communicate with the flow path 88, the flow path 314, and each solenoid valve. While the passage 316 communicates with the space between the land 304 and the land 306, the discharge passage 320 communicating with the passage 144 and the discharge port 318 is connected to the land 308 and the land ( It is communicated through the space between 310, the flow path 322, the hydraulic chamber 323 on the right side of the land 304, and as described later, the first solenoid valve 400A, the second solenoid valve 400B, and the third solenoid According to the on / off combination of the valve 400C and the fourth solenoid valve 400D, the forward shift stage corresponding to the selected position of the selection lever and the driving state of the vehicle is properly achieved in the gear shifting apparatus shown in FIG. When the selected lever is selected at the P or N position, the spool 302 is selected as the illustrated NP position and the flow path 8 8 and a flow path 144 pass through a space between the flow path 324, the land 308 and the land 310, and the flow path 88 and the flow path 314 between the land 304 and the land 306. At the same time, the orifice 326 is provided and connected to the fifth friction element 32 and the discharge passage 320 and the discharge passage 320 are spaces between the land 306 and the land 308. 322, it communicates via the hydraulic chamber 323, and the flow path 316 also communicates with the discharge flow path 320 to achieve a neutral state. When the selector lever is set to the R position, the spool 302 is switched to the R position such that the flow path 88, the flow path 314, and the flow path 328 communicate with each other through the space between the land 304 and the land 306. At the same time, the flow path 144 and the discharge flow path 320 communicate with each other through the space between the land 306 and the land 308, the flow path 322, and the hydraulic chamber 323, and the flow path 316 also discharges the flow path 320. ), The gear shifting device achieves the reverse shift state (shift stage) as described later.

The first solenoid valve 400A is a normally open three-way valve, in which a coil 402a, a valve body 40a, and a spring 406a for pressing the valve body 404a in the opening direction are disposed. In the non-excited state of the coil 402a, the valve body 404a communicates with the flow passage 410 connected to the first emergency safety valve 600, which is provided with a discharge flow passage 320 and an orifice 408, which will be described later. At the same time, the flow path 410 and the flow path 414 through which the hydraulic pressure of the flow path 316 or the flow path 328 are guided through the flow path 410 and the check valve 412 are communicated with each other. The valve body 404a is configured to block the communication between the flow path 410 and the flow path 414 and to communicate the flow path 410 with the discharge flow path 320. The second solenoid valve 400B is a normally closed three-way valve, in which a coil 402b, a valve body 404b, and a spring 406b for pressing the valve body 404b in the closing direction are disposed. In the non-excited state of the coil 402b, the valve body 404b communicates with the flow path 416 provided with the flow path 316 and the orifice 415 and connected to the second emergency safety valve 700 described later. The flow passage 416 and the discharge passage 320 are in communication with each other, and the valve body 404b communicates with the discharge passage 320 and the passage 416 in the excited state of the coil 402b. The flow path 416 is connected to the flow path 316 at the same time.

The third and fourth solenoid valves 400C and 400D are normally open three-way valves identical to the first solenoid valve 400A, and include coils 402c and 402d and valve bodies 404c and 404d therein. Springs 406c and 406c for pressing the sieves 404c and 404d in the opening direction are disposed, respectively, and the valve bodies 404c and 404d are discharge flow paths 320 in the non-excited state of the coils 402c and 402d. And the orifices 418 and 420 to block the communication between the flow paths 422 and 424 connected to the fourth friction element 30 and the third friction element 28, and at the same time the flow paths 422 and 424 The flow passage 316 communicates with the valve body 404c and 404d while the coils 402c and 402d are in an excited state, and at the same time the flow passage 320 blocks the communication between the discharge flow passage 320 and the flow passages 422 and 424. It is comprised so that 422 and 424 and the flow path 316 may communicate.

The relationship between the combination of " on " (excitation) and " off " (non-excitation) of the first to fourth solenoid valves 400A, 400B, 400C, and 400D and the gear stage is as shown in the second table. "-" In the table indicates either on or off.

TABLE 2

The flow path pressure switching valve 500 is for switching the flow path pressure to a value corresponding to the shift stage, and includes a pressure receiving surface 504 and a pressure receiving surface 506 to which the hydraulic pressure of the oil passage 314 in which the orifice 502 is installed is applied. Opposing the land 508 and the pressure receiving surface 506 at the same time as the hydraulic pressure of the pressure receiving surface 510 and the flow path 512 having the same hydraulic pressure area as the pressure receiving surface 506. A spool 518 having a land 516 having a pressure receiving surface 514 formed thereon, and a spring 520 contacting the pressure receiving surface 514 to press the spool 518 in the right direction in the second direction. When the hydraulic pressure is supplied to the oil passage 314 and the oil pressure is not supplied to the oil passage 512, the pressure acting on the pressure receiving surface 504 may resist the pressing force of the spring 520, and thus the spool 518 may be left. Direction, the flow path 156 and the discharge port communicate with each other through the space between the lands 508 and 516, When no hydraulic pressure is supplied to any of the furnace 512 and the flow path 314, or when hydraulic pressure is supplied to the flow path 512, the pressing force of the spring 520 or the pressure of this spring 520 The flow path 156 and the flow path 512 communicate with each other via the hydraulic chamber on the left side of the land 516 as the spool 518 is displaced in the right direction of the drawing due to the pressure acting on the pressure receiving surface 514. In addition, orifices 522 and 524 are provided in the flow path 512 and communicate with the flow path 424 and are connected to the first emergency safety valve 600 and the second emergency safety valve 700 described later.

The first emergency safety valve 600 is connected to the flow path 314 and has a land 610 having a pressure receiving surface 606 and a pressure receiving surface 608 on which hydraulic pressure of the oil passage 604 provided with the orifice 602 is applied. On the land 616, the pressure receiving surface 614, the pressure receiving surface 612 and the pressure receiving surface 614 having a hydraulic pressure area larger than the pressure receiving surface 608 and opposing the pressure receiving surface 608. A pressure receiving surface 618 having a hydraulic pressure area smaller than the pressure receiving surface 614 and a land 622 having a pressure receiving surface 620, and a pressure receiving surface 620. Land 628 having a pressure receiving surface 624 and a pressure receiving surface 626 having the same pressure receiving area as (), and a pressure receiving surface having a hydraulic pressure area opposite to the pressure receiving surface 626 and smaller than the pressure receiving surface ( A spool 636 is formed with a land 634 having a pressure receiving surface 632 on which 630 and a hydraulic pressure of the oil passage 512 act, and only the oil pressure of the oil passage 604 is the pressure number. When the hydraulic pressure of the flow path 410 acts only on the pressure receiving surfaces 614 and 618 on the surface 606, the spool 636 is maintained at the left end position in FIG. A flow path 638 for supplying hydraulic pressure to the first friction element 44 is maintained in communication, and in addition to this state, it is connected to a flow path 640 for supplying hydraulic pressure to the second friction element 54. The pressure receiving surface when the oil pressure is delivered to at least one of the oil passage 644 provided with the orifice 642 or the oil passage 512 (which is in communication with the oil passage 424 for supplying oil pressure to the third friction element 28). This hydraulic pressure acts on the 626 or the pressure receiving surface 632 so that the spool 636 is displaced to the right of the drawing, and the flow path 638 passes through the space between the land 622 and the land 628 to discharge the flow path 320. The first friction element 44 is configured to be released in an instant.

In addition, the space between the land 610 and the land 616 communicates with the discharge port. In addition, the pressure receiving surface 606 may be changed to supply hydraulic pressure, and a spring may be provided to press the spool 636 in the left direction in the drawing. In this structure, the oil passage 604 for guiding the hydraulic pressure to the pressure receiving surface 606 can be omitted, and the hydraulic circuit can be simplified. Wherein the pressure receiving surface (614, 618) is a detection means for detecting the hydraulic pressure supplied to the first friction element 44 in the flow path, the pressure receiving surface (626, 630) the second friction in the flow path (416, 640) As means for detecting the oil pressure supplied to the element 54, the hydraulic surface 632 acts as detection means for detecting the oil pressure supplied to the third friction element 28 in the flow path 424, respectively. The pressure receiving surface serves as a switching means for switching the position of the spool 636.

The second emergency safety valve 700 opposes the land 706 and the pressure receiving surface 704 having the pressure receiving surface 702 and the pressure receiving surface 704 and has a hydraulic pressure area larger than the pressure receiving surface 704. A land 712 having a pressure receiving surface 708 and a pressure receiving surface 710, a pressure receiving surface 714 opposite to the pressure receiving surface 710 and having a hydraulic pressure area smaller than the pressure receiving surface 710. A land 718 having a pressure receiving surface 716, having a pressure receiving surface 720 and a pressure receiving surface 722 opposite to the pressure receiving surface 716 and having the same hydraulic pressure area as the pressure receiving surface 716. A spool in which a land 724, a pressure receiving surface 726 having a hydraulic pressure area smaller than the pressure receiving surface 722 and a land 730 having a pressure receiving surface 728, is formed. One side of the flow path 736 provided with the 732 and having oil pressure delivered to only the flow path 604 and the flow path 416 and having a flow path 512b or an orifice 734 communicated with the flow path 422. When only the hydraulic pressure is delivered, the spool 732 is held at the left end position in FIG. 2 due to the area difference of the pressure receiving surface on which each hydraulic pressure acts, so that the flow path 416 and the second friction element 54 A flow path 640 for supplying hydraulic pressure is maintained in a communication state through a space between the pressure receiving surface 714 and the land 712, and the oil pressure is delivered to the flow paths 604 and 416 and at the same time the flow path 512 is provided. When the hydraulic pressure is also delivered to both sides of the flow path and the flow path 736, the spool 732 is displaced to the right side of the drawing so that the flow path 640 communicates with the discharge flow path 320 through the space between the land 718 and the land 724. The second friction element 54 is configured to open instantly.

The hydraulic chamber on the right side of the land 706 communicates with the discharge port. In addition, the spring may be replaced by supplying hydraulic pressure to the pressure receiving surfaces 704 and 708 and pressing the spool 732 in the left direction in the drawing. In such a structure, the oil passage 604 for guiding the hydraulic pressure to the pressure receiving surface 702 can be omitted, and the hydraulic circuit can be simplified.

Here, the pressure receiving surfaces 710 and 714 are detection means for detecting the hydraulic pressure supplied from the flow passage 410 to the second friction element 54, wherein the pressure receiving surfaces 722 and 726 are formed in the flow passage 422. As the detection means for detecting the hydraulic pressure supplied to the four friction elements 30, the pressure receiving surface 728 acts as detection means for detecting the hydraulic pressure supplied to the third friction element 28 in the flow path 424 and At the same time, each of the pressure receiving surfaces serves as a switching means for switching the position of the spool 732.

The first and second emergency safety valves 600 and 700 prevent the lock of the transmission by engaging three or more friction elements at the same time even if the solenoid valve malfunctions when some forward gear stage is achieved. At the same time, the vehicle is forcibly shifted to a gear shift stage of the second, third, or fourth speed to enable the vehicle to run.

Next, the operation of the hydraulic control device will be described.

When the driver sets the above-described selection lever disposed in the vehicle interior of the vehicle to the P or N position, the spool 302 of the manual valve 300 mechanically or electrically connected to the selection lever is also linked to the selection lever to the PN position. Is set. Then, when the engine is started, the operating pressure pressurized by the oil pump 86 is discharged to the flow path 88 to generate hydraulic pressure in the flow path 88. The hydraulic pressure of the oil passage 88 acts on the pressure receiving surfaces 104 and 108 of the pressure regulating valve 100 via the oil passage 148 and at the same time the land 308 and the land of the oil passage 324 and the manual valve 300 ( It acts on the pressure receiving surface 102 of the pressure regulating valve 100 via the space between 310 and the flow path 144. The spool 138 of the pressure regulating valve 100 is stable at a position where the pressure acting on each of the pressure receiving surfaces and the pressing force of the spring 140 are in equilibrium, and between the lands 130 and 136 via the flow path 158. A part of the hydraulic pressure guided to the space is discharged to the flow path 164 and the flow path 166 so that the hydraulic pressure in the flow path 88 is adjusted to the lowest predetermined pressure (called the first flow pressure). In addition, the operating pressures of the oil passage 88 and the oil passage 164 are guided to the torque converter control valve 200 via the oil passage 160 and are controlled by the hydraulic control action of the torque converter control valve 200 described above. 12, a predetermined operating pressure is supplied via the flow path 168. In addition, the oil pressure of the oil passage 88 passes through the space between the land 304 and the land 306 of the manual valve 300, the oil passage 314 to the left end hydraulic chamber of the oil pressure switching valve 500, and the oil passage 604. Is delivered. The hydraulic pressure guided to the hydraulic chamber acts on the pressure receiving surface 504 and resists the pressing force of the spring 520 to displace the spool 518 to the left end position of the second degree so that the flow passage 156 and the discharge passage communicate with each other. The hydraulic pressure guided to the flow path 604 is led to a space between the right end hydraulic chamber of the first emergency safety valve 600 and the land 712 and the land 706 of the second emergency safety valve 700. By displacing the spools 636 and 732 of both emergency safety valves 600 and 700 to the left end position of FIG. 2, the flow path 410 and the flow path 638, and the flow path 416 and the flow path 640 communicate with each other. do.

At this time, all of the first to fourth solenoid valves 400A, 400B, 400C, and 400D are kept in an off (non-excited) state. Here, when the driver operates the selection lever to select the D4 position, the manual valve 300 is set to the D position, and the flow passage 324 is blocked by the land 310 so that the flow passage 144 and the flow passage 322 are closed. In communication with each other, the hydraulic pressure of the right end hydraulic chamber of the pressure regulating valve 100 is discharged through the passage 322 and the discharge passage 320. The flow passage 88 also communicates with the flow passage 316 via the space between the land 304 and the land 306 of the manual valve 300, and the hydraulic pressure of the flow passage 316 passes through the flow passage 152. Guided to the space between land 112 and land 118 of 100. Then, the spool 138 is stable at a position where the force acting on the pressure receiving surfaces 110, 114 and the pressure receiving surfaces 104, 108 and the pressing force of the spring 140 are in equilibrium, A part of the oil pressure is discharged from the oil passage 164 and the oil passage 166 to adjust the oil pressure of the oil passage 88 to a relatively high pressure (for example, 10 kg / cm ² ) at a predetermined pressure (called a second oil pressure). The hydraulic pressure of the flow path 316 is guided to the second to fourth solenoid valves 400B, 400C, and 400D, and is also guided to the first solenoid valve 400A via the check valve 412 and the flow path 414.

The flow path 314 is maintained in communication with the flow path 88 as in the case of the N.P position.

In addition, the selection lever is set to the D4 position, and as shown in the first table, in order to achieve the first speed shift stage by combining the first friction element 44 and the fourth friction element 30, the above-described electronic control is performed. From the device, the first to third solenoid valves 400A, 400B and 400C are kept in an unexcited state, as shown in the second table, and the fourth solenoid valve 400D is made to be in an excited state from an unexcited state, and And a signal for communicating the flow path 414 and the flow path 410, the flow path 316 and the flow path 422 with only the third solenoid valves 400A and 400C open. The hydraulic pressure guided to the flow path 410 is led to the first friction element 44 via the space between the land 616 and the land 622 of the first emergency safety valve 600, the flow path 638, and The hydraulic pressure guided to the flow path 422 is directed to the space between the land 724 and the land 730 of the second emergency safety valve 700 via the fourth friction element 30 and the flow path 736, but both frictions When the elements 44 and 30 are rapidly coupled at the second flow path of relatively high pressure, there is a possibility that a shank at the time of engagement may occur, so that the first solenoid valve 400A is drawn immediately before the first friction element 44 is engaged. Immediately before the fourth friction element 30 engages, each of the third solenoid valves 400C is first excited with a predetermined impact coefficient, and then the laminar coefficient is gradually reduced to finally become a non-excited state. That is, when the hydraulic pressure of the flow path 638 and the flow path 422 raises gradually, the said shank can be reduced.

Next, when the vehicle starts to run and a shift up to the second speed shift stage is instructed by an electronic control device (not shown) based on the throttle valve opening degree signal or the vehicle speed signal, as shown in the first table, the second The first, second, and fourth solenoid valves 400A, 400B, 400D are excited to engage the friction element 54 and the fourth friction element 30, and the third solenoid valve 400C is closed. A signal for making it excited is output from the electronic control apparatus. Since the first solenoid valve 400A is switched from the non-excited state to the excited state, the flow path 410 and the discharge flow path 320 communicate with each other to discharge the hydraulic pressure of the flow path 410 and the first friction element 44. Is released.

Since the second solenoid valve 400B is switched from the non-excited state to the excited state, the oil passage 316 and the oil passage 416 communicate with each other, and the hydraulic pressure guided to the oil passage 416 is controlled by the second emergency safety valve 700. The space between the land 712 and the land 718 passes through the flow path 640 to the second friction element 54 to engage the friction element 54 and at the same time, the hydraulic pressure of the flow path 640 flows through the flow path 640. It is also passed through 644 to the space between the land 628 and the land 634 of the first emergency safety valve 600. However, since the hydraulic pressure applied between the lands 616 and 622 is reduced, the force in the right direction in the drawing of the hydraulic pressure guided to this space and acting on the pressure receiving surfaces 626 and 630 is the land 610. The pressure in the left direction in the drawing due to the second flow pressure acting on the pressure receiving surface 606 of the substrate cannot be resisted, and the spool 636 is maintained at the position on the left side in FIG. In addition, in the case of the second solenoid valve 400B, the second friction element 54 suddenly engages when suddenly excited, and there is a possibility that a shank may occur, so that the impact rate of the solenoid valve 400B is gradually changed. The hydraulic pressure of the flow path 416 is gradually raised, and finally the second flow pressure can be reduced to reduce the shank.

Since the third solenoid valve 400C is kept in the non-excited state, as in the case of the first speed shift stage, the flow path 316 communicates with the flow path 422 and the fourth friction element 30 is kept in the engaged state.

Since the fourth solenoid valve 400D is kept in the excited state and the flow path 424 is in communication with the discharge flow path 320, the third friction element 28 is kept in the released state.

Next, when the vehicle speed further increases, and the electronic control device instructs the upshift from the second speed to the third speed shift stage, as shown in the first table, the fourth friction element 30 and the third friction are shown. A signal for energizing the first solenoid valve 400A to engage the element 28 and non-exciting the second to fourth solenoid valves 400B, 400C, 400D is sent to the electronic control device. Is output.

Since the first solenoid valve 400A is kept in an excited state, the flow passage 410 communicates with the discharge flow passage 320 as in the case of the second speed shift stage.

Since the second solenoid valve 400B is switched from the excited state to the non-excited state, the flow path 416 communicates with the discharge flow path 320 and the second friction element 54 is released.

Since the third solenoid valve 400C is maintained in the non-excited state, the flow path 422 and the flow path 316 are kept in communication and the fourth friction element is kept in the engaged state.

Since the fourth solenoid valve 400D is switched from the excited state to the non-excited state, the oil passage 316 and the oil passage 424 communicate with each other, and the oil pressure delivered to the oil passage 424 is delivered to the third friction element 28. To engage this friction element 28. The oil pressure of the oil passage 424 is also passed through the oil passage 512 to the left oil pressure chamber of the oil pressure switching valve 500, through the oil passage 512b to the left oil pressure chamber of the first emergency safety valve 600, and the second emergency. It is also directed to the left end hydraulic chamber of the safety valve 700. The hydraulic pressure guided to the left end hydraulic chamber of the flow path pressure switching valve 500 acts on the pressure receiving surface 514 and acts on the pressure receiving surface 504 of the land 508 in cooperation with the pressing force of the spring 520. In response to pressure, the spool 518 is displaced to the right side of the drawing to communicate the flow passage 512 with the flow passage 156. The hydraulic pressure guided from the oil passage 512 to the oil passage 156 is led to the space between the land 118 and the land 124 of the voltage valve 100 and acts on the pressure receiving surfaces 116, 120, so The spool 138 of the valve 100 balances the force acting on the pressure receiving surfaces 116, 120, the pressure receiving surfaces 110, 114, and the pressure receiving surfaces 104, 108 with the pressing force of the spring 140. Stable at a position to achieve a predetermined pressure, and discharge a part of the oil pressure of the oil passage 158 from the oil passage 164 and the oil passage 166, and the oil pressure of the oil passage 88 is lower than the second oil pressure and higher than the first oil pressure. Pressure is regulated by pressure (called third euro pressure).

The hydraulic pressure guided to the left end hydraulic chamber of the first emergency safety valve 600 acts on the pressure receiving surface 632 of the land 634, but is led to the right end hydraulic chamber of the valve 600 via the flow path 604 to supply pressure. Since the hydraulic force acting on the receiving surface 606 cannot be overcome in relation to the area difference, the spool 636 is maintained at the position on the left side in FIG.

The hydraulic pressure guided to the left end hydraulic chamber of the second emergency safety valve 700 acts on the pressure receiving surface 728 of the land 730, and passes through the flow path 736 to the space between the land 724 and the land 730. The spool 732 is pushed to the right in combination with the hydraulic force acting on the pressure receiving surfaces 722, 726, but is guided to the space between the land 706 and the land 712 via the flow path 604 to be pressured. Since the pressing force in the left direction by the hydraulic force acting on the receiving surfaces 704 and 708 is large, the spool 732 is held in the position on the left side in FIG. Further, when the vehicle speed is further increased and a shift from the third speed shift stage to the fourth speed shift stage is instructed by an electronic control device (not shown), as shown in the first table, the second friction element 54 and A signal for exciting the first to third solenoid valves 400A, 400B and 400C to engage the third friction element 28 and de-exciting the fourth solenoid valve 400D is output from the electronic control device. do. Since the first solenoid valve 400A is kept in the excited state, the flow passage 410 communicates with the flow passage 320 as in the case of the third speed shift stage.

Since the second solenoid valve 400B is switched from the empty state to the excited state, the oil passage 316 and the oil passage 416 communicate with each other, and the oil pressure of the oil passage 416 is the land 712 of the second emergency safety valve 700. ) And the space between the land 718 and the second friction element 54 via the flow path 640 to bring the friction element 54 in the engaged state and at the same time through the flow path 644 to the first emergency safety Guided to the space between the land 628 and the land 634 of the valve 600 acts on the pressure receiving surface (626, 630).

Since the third solenoid valve 400C is switched from the non-excited state to the excited state, the flow path 422 is blocked from communicating with the flow path 316 to communicate with the discharge flow path 320, and the hydraulic pressure of the flow path 736 is discharged. At the same time, the fourth friction element 30 is released.

As the fourth solenoid valve 400D is maintained in the non-excited state and the flow path 424 is kept in communication with the flow path 316, the third friction element 28 is kept in the engaged state, and the flow pressure switching valve ( Hydraulic pressure is also supplied to the left end hydraulic chamber of 500) (the oil pressure of the flow path 88 is maintained at the third euro pressure), the left end hydraulic chamber of the first emergency safety valve 600, and the left end hydraulic chamber of the second emergency safety valve 700. This continues to be delivered.

In addition, since the hydraulic pressure is guided to the left end hydraulic chamber of the first emergency safety valve 600 and the space between the land 628 and the land 634 in the state where the fourth speed shift stage is achieved, the angle at which this hydraulic pressure acts. In the relation between the pressure receiving surfaces 632, 626, 630 and the pressure receiving area of the pressure receiving surface 606 in which the hydraulic pressure guided to the right end hydraulic chamber of the valve 600 via the flow path 604, the pressure receiving surface The hydraulic force acting on the 632, 626, and 630 resists the hydraulic force acting on the pressure receiving surface 606, thereby displacing the spool 636 to the right of FIG. 2, and the oil passage 638 discharges the oil passage 320. Is configured to communicate).

The upshift operation from the first speed shift stage to the fourth speed shift stage has been described above, but the downshift operation from the fourth speed shift stage to the first speed shift stage is only performed in the completely reverse order of the upshift. Are omitted.

In addition, when the selection lever is set at the D3, D2, or L position, the shift range corresponding to the position is determined only by a command from the electronic control device, and the manual valve 300 is held at the D position to provide hydraulic pressure. The description is omitted since there is no change.

Next, when the driver sets the selector lever to the R position, the spool 302 of the manual valve 300 is also moved to the R position, and the flow path 144 is a space between the land 306 and the land 308, the flow path. 322 and the right end hydraulic chamber 323 of the manual valve 300 communicate with the discharge flow path 320. In addition, the flow path 316 also communicates with the discharge flow path 320 via the right end hydraulic chamber 323. Therefore, only the hydraulic pressure which is guided to the space between the land 106 and the land 112 of the pressure regulating valve 100 through the flow path 148 through the pressure regulating valve 100 and acts on the pressure receiving surfaces 104 and 108. By guiding, the spool 138 is stable at a position where the hydraulic force acting on this pressure receiving surface is balanced with the pressing force of the spring 140, and the hydraulic pressure of the flow path 88 is highest (for example, 16 kg / cm < 2 >). ) To a predetermined pressure (referred to as fourth flow pressure). In addition, the flow path 88 communicates with the flow path 314 and the flow path 328 through the space between the land 304 and the land 306 of the manual valve 300, and the hydraulic pressure guided to the flow path 314 is Similarly to when the shift stage of the forward is achieved, the hydraulic pressure guided to the first and second emergency safety valves 600 and 700 through the flow path pressure switching valve 500 and the flow path 604, and to the flow path 328 Is led to the fifth friction element 32 to bring the friction element 32 into engagement and at the same time to the check valve 412. When the selector lever is set to the R position, as shown in the second table, the first solenoid valve 400A is in the non-excited state, so that the hydraulic pressure delivered to the check valve 412 is the oil passage 414 and the oil passage 410. And the first friction element 44 through the space between the land 616 and the land 622 of the first emergency safety valve 600 and the flow path 638, the friction element 44 is engaged The inflection stage of reverse is achieved.

Here, in the hydraulic control device shown in FIG. 2, at the lowest first flow pressure when neutral, and when the gear stages of the first speed and the second speed are achieved, the second flow pressure is relatively high. The hydraulic pressure of the flow path 88 is at the relatively low third euro pressure higher than the first euro pressure when the gear shift stage is achieved, but lower than the second euro pressure, and the highest fourth euro pressure when the reverse shift stage is achieved. The engine is configured to be switched, but the engine speed is not transmitted to the output shaft of the transmission, but the first speed at which the Jenjin drives the pump 86 at a neutral time with the smallest power loss and the relatively large torque is transmitted. And at the second speed shift stage, the flow pressure is relatively high and the engagement force of the friction elements is relatively large to prevent slippage. In the third and fourth speed shift transmission torques, the transmission torque is relatively small. The low pressure is set relatively low to reduce power loss for driving the pump 86, and at the reverse shift stage with the largest transmission torque, the flow path pressure is the highest to prevent slippage of the friction element.

In addition, by smoothly controlling the first to fourth solenoid valves 400A, 400B, 400C, 400D, the hydraulic pressure supplied to the friction element corresponding to each solenoid valve and the hydraulic pressure discharged can be smoothly achieved. .

Next, the operation of the first and second emergency safety valves 600 and 700 in the case where a failure occurs in the electronic control device or the solenoid valve and the solenoid valve malfunctions will be described.

The second solenoid valve 400B malfunctions when the first to third solenoid valves 400A, 400B and 400C are not excited and the fourth solenoid valve 400D is excited to achieve the first speed shift stage. When it is excited, the flow path 316 and the flow path 416 are in communication, and the hydraulic pressure guided to the flow path 416 is a space between the land 712 and the land 718 of the second emergency safety valve 700. The friction element 54 is guided to the second friction element 54 through the coupling, but at the same time the land 628 and land of the first emergency safety valve 600 are passed through the flow path 640 and the flow path 644. Guided to the space between the 634, the hydraulic pressure acting on the pressure receiving surface (626, 630) in addition to the pressing force in the right direction by the hydraulic pressure acting between the pressure receiving surface (614, 618) Left by hydraulic pressure acting on the pressure receiving surface 606 by the pressing force in the right direction acts on the spool 636 Against the force of the direction in which the position of the spool 636, FIG. 2 is changed over to the right. Therefore, since the flow path 638 is in communication with the discharge flow path 320, the first friction element 44 is released and only the second friction element 54 and the fourth friction element 30 are coupled to each other. The gear shift in the gearbox is achieved.

In addition, if the fourth solenoid valve 400D malfunctions in the state where the first speed shift stage is to be achieved and the element is malfunctioned, the oil passage 316 and the oil passage 424 communicate with each other and the hydraulic pressure is guided to the third friction element 28. The friction element 28 is engaged with each other, and is led to the respective left end hydraulic chambers of the first emergency safety valve 600 and the second emergency safety valve 700 via the flow path 512b, and the first emergency safety valve 600 is provided. In the same manner as above, the spool 636 is switched in the right direction as shown by the hydraulic pressure applied to the pressure receiving surface 632 and the pressure receiving surfaces 614 and 618. In this case, the spool 732 of the second emergency safety valve 700 is not switched to the discharge position on the right side of the drawing, but the second solenoid valve 400B is provided so that hydraulic pressure is not supplied to the flow path 416. Therefore, the second friction element 54 does not engage. Thus, since the flow path 638 communicating with the first friction element 44 communicates with the discharge flow path 320, the second friction element 44 is released and the fourth friction element 30 and the third friction element 28 are separated. ) Is engaged, and the third speed shift stage is achieved.

In addition, when the second solenoid valve 400B is excited and the fourth solenoid valve 400D is not excited in the state where the first speed shift stage is to be achieved, only the fourth solenoid valve 400D is in addition to the malfunctioning state. Since the solenoid valve 400B malfunctions and the flow path 316 and the flow path 416 communicate with each other, all the flow paths 410, 416, and 422 communicate with each solenoid valve and each friction element 28, 30, 44, and 54. , 424). Then, hydraulic pressure acts on all of the pressure receiving surface 728, the pressure receiving surfaces 722, 726, and the pressure receiving surfaces 710, 714 of the second emergency safety valve 700 to move the spool 732 in the right direction. By pressurizing, the spool 732 is switched to the right position in the figure so that the hydraulic pressure of the flow path 640 is discharged through the discharge flow path 320 so that the second friction element 54 is maintained in the released state. In addition, since the hydraulic pressure acts on the pressure receiving surface 632 and the pressure receiving surfaces 614 and 618 on the first emergency safety valve 600, the hydraulic pressure acts on the pressure receiving surface to the right in the drawing. The pressing force becomes larger than the pressing force in the left direction in the drawing due to the hydraulic pressure acting on the pressure receiving surface 606, the spool 636 is switched to the right position so that the flow path 638 communicates with the discharge flow path 320, and the first pressure is applied. The friction element 44 remains in the released state. Thus, only the fourth friction element 30 and the third friction element 28 are engaged to achieve the third speed shift stage.

Next, the first solenoid in a state where the second speed shift stage at which the first, second and fourth solenoid valves 400A, 400B, 400D are excited and the third solenoid valve 400C is not excited is to be achieved. When the valve 400A is not excited, hydraulic pressure is delivered to the pressure receiving surfaces 626 and 630 of the first emergency safety valve via the oil passage 644, and the oil passage 316 and the oil passage 410 communicate with each other. As the oil pressure of 410 is guided to the space between the land 616 and the land 622, the pressure in the right direction in the drawing by those oil pressures acts on the pressure receiving surface 606 in the left direction in the drawing. The position of the spool 636 is switched in the right direction in the figure by being larger than the pressing force in the drawing. Therefore, communication between the flow path 410 and the flow path 638 is blocked, and the flow path 638 communicates with the flow path 320 so that only the second friction element 54 and the fourth friction element 30 are in a coupled state. Is maintained, and the second speed shift stage is maintained.

In addition, when the fourth solenoid valve 400D malfunctions in the state where the second speed shift stage is to be achieved, the flow path 316 and the flow path 424 communicate with each other, and the oil pressure of the flow path 424 is controlled by the third friction element. Guide 28 engages this friction element and, at the same time, flows through the flow path 512b to each of the left end hydraulic chambers of the first and second emergency safety valves 600, 700. Then, the hydraulic pressure acts on all of the pressure receiving surfaces 728, the pressure receiving surfaces 722, 726, and the pressure receiving surfaces 710, 714 of the second emergency safety valve 700, and thus the spool 732 by the pressing force. ) Is switched to the right position in the figure so that the flow path 640 communicates with the discharge flow path 320 and the second friction element 54 is released. On the other hand, the hydraulic pressure is also delivered to the pressure receiving surface 632 of the first emergency safety valve 600 via the flow path 512b, but the pressure receiving surfaces 626 and 630 are switched by the switching of the second emergency safety valve 700. Since the hydraulic pressure is not delivered to the space between them, and the first solenoid valve 400A is excited and no hydraulic pressure is also delivered to the space between the pressure receiving surfaces 614 and 618, the spool 636 is positioned at the left side in the drawing. Is maintained, but the hydraulic supply to the first friction element 44 is not made so that the friction element remains in the released state. Thus, the fourth friction element 30 and the third friction element 28 are engaged to achieve a third speed shift stage.

Furthermore, when the first and fourth solenoid valves 400A and 400D are not excited together in a state where the second speed gear stage is to be achieved, the spool 636 and the second emergency of the first emergency safety valve 600 are not excited. As the positions of the spool 732 of the safety valve 700 are switched together in the right direction, the flow passage 638 communicating with the first friction element 44 and the flow passage 640 communicating with the second friction element 54 are provided. ) Are in communication with the discharge flow path 320 so that the friction elements 44 and 54 are released, and the fourth friction element 30 and the third friction element 28 are coupled to each other. Is achieved.

Next, the first solenoid valve 400A is in a state in which a third speed shift stage at which the first solenoid valve 400A is excited and the second to fourth solenoid valves 400B, 400C, and 400D is not excited is to be achieved. ) Is not excited, the oil passage 316 and the oil passage 410 communicate with each other, and the oil pressure of the oil passage 410 passes into the space between the land 616 and the land 622 of the first emergency safety valve 600. Is delivered. At this time, since the hydraulic pressure is guided to the pressure receiving surface 632 via the oil passage 512b, the position of the spool 636 is switched to the right side in the drawing in relation to the hydraulic pressure area with the pressure receiving surface 606, and the oil passage ( 638 is in communication with the discharge flow path 320, the hydraulic pressure is not supplied to the friction element 44, the first friction element 44 and the second friction element 54 are released, and the fourth friction element 30 ) And the third friction element 28 are held in engagement to maintain the third speed shift stage.

Further, when the second solenoid valve 400B is excited in a state where the third speed shift stage is to be achieved, the flow path 316 and the flow path 416 communicate with each other, and the hydraulic pressure is reduced to the land of the second emergency safety valve 700. Guided to the space between 712 and land 718. At this time, hydraulic pressure is also applied to the pressure receiving surface 728 and the pressure receiving surfaces 722 and 726, and the position of the spool 732 is switched to the right side of the drawing as described above, and communicates with the second friction element 54. The flow path 640 communicates with the discharge flow path 320, and no hydraulic pressure is supplied to the friction element 54, and the third speed shift stage is maintained as described above.

Furthermore, when the first solenoid valve 400A is in the element state and the second solenoid valve 400B is in the excited state while the third speed shift stage is to be achieved, the spool 636 of the first emergency safety valve 600 is activated. ) And the position of the spool 732 of the second emergency safety valve 700 are switched together in the right direction, the flow path 638 and the flow path 640 communicate with the discharge flow path 320 and the friction elements 44, 54. ), No hydraulic pressure is supplied, and the third speed shift stage is maintained.

Next, when the first to third solenoid valves 400A, 400B, and 400C are excited and the fourth speed shift stage at which the fourth solenoid valve 400D is not excited is to be achieved, the first solenoid valve 400A is If it is not excited, the flow path 316 and the flow path 410 will be in communication, but in the 4th speed shift stage, the position of the spool 636 of the 1st emergency safety valve 600 will be the pressure receiving surface 632 and pressure. Since the hydraulic pressure acting on the receiving surfaces 626 and 630 is previously switched to the right side of the drawing, the hydraulic pressure of the flow path 410 is not supplied to the first friction element 44, but the second friction element 54 is provided. And only the third friction element 28 remains engaged, so that the fourth speed shift stage is maintained.

In addition, when the third solenoid valve 400C is in the element state in the state where the fourth speed shift stage is to be achieved, the oil passage 316 and the oil passage 422 communicate with each other, and the hydraulic pressure is delivered to the fourth friction element 30. The friction element 30 is brought into engagement, and at the same time, it is led to the space between the land 724 and the land 730 of the second emergency safety valve 700 via the flow path 736. Thus, the hydraulic pressure acts on all of the pressure receiving surfaces 722, 726, the pressure receiving surfaces 728, and the pressure receiving surfaces 710, 714 of the second emergency safety valve 700, thereby positioning the spool 732. Is switched to the right side of the drawing, the flow path 640 communicates with the discharge flow path 320 to release the second friction element 54, and only the fourth friction element 30 and the third friction element 28 are coupled to each other. To achieve the third speed shift stage.

Furthermore, when the first and third solenoid valves 400A and 400C are in the element state in the state where the fourth speed shift stage is to be achieved, the flow path 410 and the flow path 422 communicate with the flow path 316, but The position of the spool 636 of the first emergency safety valve 600 is already switched to the right direction in the drawing, and the flow path in which the spool 732 of the second emergency safety valve 700 also communicates with the fourth friction element 30. As the hydraulic pressure is supplied to 422 and is switched in the right direction of the drawing, the second friction element 54 is released, and only the fourth friction element 30 and the third friction element 28 are engaged. Three speed stages are achieved.

The above embodiment includes a first emergency safety valve 600 and a second emergency safety valve 700, and if three or more friction elements are likely to be coupled at the same time due to failure of the electronic control device or solenoid valve, two frictions may be used. It is configured to leave the elements and release other friction elements, so that three or more friction elements are engaged at the same time and the transmission mechanism is locked to prevent the wheel of the vehicle from being suddenly fixed or being completely inoperable. Has an effect.

Further, in the configuration of the above embodiment, since the solenoid valve is provided corresponding to each friction element, it is possible to precisely control the hydraulic pressure supplied to the friction element and the hydraulic pressure discharged by the shock control of each solenoid valve, Reduction can be aimed at.

In this embodiment, as the first to fourth solenoid valves, a three-way solenoid valve of a ball valve type is used as shown in FIG. 2, and the total number of spool valves of the hydraulic control device is higher than that of the conventional automatic transmission. As a result, it is possible to minimize the probability that the solenoid valve and the spool valve stick.

Furthermore, in the present embodiment, when the manual valve 300 is set to the N and P positions, the oil pressure of the oil passage 88 by the pressure regulating valve 100 is adjusted to the first oil pressure, so that the rotation of the ene in the neutral state is performed. Even if the speed increases, the oil pressure of the oil passage 88 does not increase more than necessary, and there is an effect of preventing the occurrence of abnormal sounds.

In addition, the present embodiment includes a flow path pressure switching valve 500, and when the speed change stages of the first speed and the second speed are achieved, the pressure is adjusted to a relatively high second flow pressure, and the speed shift of the third speed and the fourth speed is performed. When the stage is achieved, it is regulated by a relatively low third euro pressure, so that the coupling force of the friction element can be matched to the magnitude of the transmission torque, and the loss of engine output for driving the pump 86 can be minimized. Has the effect.

In addition, in the above embodiment, the first emergency safety valve 600 communicates with the first solenoid valve 400A and the first friction element 44, and the second emergency safety valve 700 is the second solenoid valve. Although each of the first emergency safety valve 600 and the second emergency safety valve 700 is installed in the flow path communicating 400B and the second friction element 54, the installation position is not limited to the above. In a position where simultaneous coupling of two or more friction elements is prevented, the first emergency safety valve 600 is connected to the first solenoid valve 400A and the first friction element 44, and the second solenoid valve 400B. And a flow path communicating with the second friction element 54, or a flow path between the fourth solenoid valve 400D and the third friction element 28, and installing the second emergency safety valve 700. The flow path communicating the second solenoid valve 400B and the second friction element 54, the third solenoid valve 400C and the The first emergency safety valve 600 is not provided in any of the flow paths communicating with the fourth friction element 30 or the flow path between the fourth solenoid valve 400D and the third friction element 28. Even if provided in a flow path, the effect similar to a present Example is acquired.

Further, in the above embodiment, since the first and second emergency safety valves as the first and second switching valves are spool valves, the detection means for detecting the oil pressure in each flow path communicating with the solenoid valve and the friction element and the spool valve are switched. Although the pressure receiving surface of the spool valve was used as a switching means to be used, a pressure sensor serving as a detection means is provided in each of the flow paths, and the emergency safety valve, for example, an electronic switching valve or the like, is switched on and off depending on the output of the sensor. Even if it is configured to switch states, the effect similar to this embodiment is acquired.

According to the configuration of the present invention, hydraulic pressure is delivered to the first flow path and the second flow path at the same time due to a failure or malfunction of the first shift device or the second shift device. The switching valve is switched to the discharge position at which the hydraulic pressure of the first friction element is discharged, and a configuration for preventing the first friction element and the second friction element from being engaged at the same time is necessary without installing the switching means in each flow path. Since the minimum number of parts can be increased, the increase in cost and the increase in the probability of occurrence of defects in the valve stick increase hydraulic circuit can be suppressed low, and the hydraulic circuit can be simplified.

Claims (2)

First and second friction elements coupled to different transmission stages, main flow paths 88 and 316 connected to the oil pump 86, and first and second connections to the oil pump via the main flow paths, respectively. Two solenoid valves 400A and 400B, flow paths 410 and 638 communicating the first friction element 44 and the first solenoid valve 400A, the second friction element 54 and the second A hydraulic control apparatus for an automatic transmission for a vehicle having flow paths 416 and 640 communicating with a solenoid valve 400B, wherein the hydraulic pressure is applied to the first friction element formed between the flow paths 410 and 638 and connected to the flow path. And a first emergency safety valve (600) having a supply position for supplying gas and a discharge position for discharging hydraulic pressure from the first friction element, wherein the first emergency valve has a spool (636) for switching the supply position and the discharge position. ) And a pressure to press the spool to the supply position side It is made of a receiving surface 606, the spool is supplied to the pressure receiving surface (614, 618) and the second friction element for receiving the hydraulic pressure supplied to the first friction element to press the spool in the direction of the hydraulic discharge position And a pressure receiving surface (626, 630) for receiving the hydraulic pressure to pressurize the spool in the hydraulic discharge position direction. 2. The pressure receiving surface 606 of claim 1, wherein the pressure receiving surface 606 is a main pressure receiving surface 606 that receives hydraulic pressure from the main flow passage 88 and presses the spool toward the supply position, and an effective hydraulic pressure of the main pressure receiving surface. The area is larger than the effective hydraulic pressure area of the pressure receiving surfaces 614 and 618 and the effective hydraulic pressure area of the pressure receiving surfaces 626 and 630, and the effective hydraulic pressure areas of the pressure receiving surfaces 614 and 618 and the pressure receiving surface. A hydraulic control apparatus for an automatic transmission for a vehicle, characterized in that it is formed smaller than the sum of the effective hydraulic pressure areas of the (626, 630).

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