KR920006024B1 - Hydraulic control of automatic transmission for vehicles - 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 the configuration of one embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

28: third friction element (first clutch) 30: fourth friction element (second clutch)

44: first friction element (first brake) 54: second friction element (second brake)

86: Oil Pump

400A: first solenoid valve (first shift device)

400B: second solenoid valve (second shift device)

400C: 3rd solenoid valve (4th shift device)

400D: 4th solenoid valve (3rd shift device)

614, 618: first pressure receiving surface (first detecting means)

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

632: second pressure receiving surface (third detection means)

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

728: fifth pressure receiving surface (third detecting means)

722, 726: 6th pressure receiving surface (4th detection means)

600: first emergency safety valve (first switching valve)

636: first spool (first switching means)

700: second emergency safety valve (second switching valve)

732: second spool (second switching means)

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

A first, second, third, and fourth friction element and a hydraulic fluid source and a flow path communicating with the first friction element, the first friction element switching 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 in accordance with a driving state of the vehicle; A third shift device installed in the flow passage communicating with the third friction element and switching hydraulic supply and discharge to the third friction element according to the driving state of the vehicle, and a flow passage communicating the hydraulic source and the fourth friction element. A fourth shifting device installed in the fourth friction element to switch hydraulic supply and discharge in accordance with the driving state of the vehicle, and selectively coupling two of the first to fourth friction elements. Achieve The vehicle automatic transmission that has a hydraulic pressure supply to the discharge of the U.S. Patent, each friction element is configured to be switched by the on / off operation of the solenoid valve to the shift valve spool of each device. If three or more friction elements are combined at the same time due to a failure of the solenoid valve or an electronic control unit controlling the solenoid valve, a contradiction occurs in the torque transmission path of the gear train of the automatic transmission, causing the input / output shaft to lock or In order to be damaged, a relay valve is provided in each flow path which communicates a hydraulic source and each shift apparatus.

For example, when the clutch 54 and the brake 58 are engaged and the first speed shift stage is achieved, the second relay valve, the third relay valve, and the fourth relay valve operate to operate the clutch 54 from the hydraulic source. The hydraulic pressure supplied to the engaging elements other than the) and the brake 58 is cut off in front of the shift device, and the hydraulic pressures of the engaging elements are all discharged.

Therefore, what is described in the said publication has the effect that a hydraulic pressure is not supplied to three or more friction elements at the same time, and a transmission does not break or become locked.

However, in order to achieve the above object, the above configuration requires relay valves to be installed in each flow path that communicates between the hydraulic source and each shift device, so that the cost increases due to the complexity of the hydraulic circuit and the increase in the number of parts. There is a disadvantage that the rise of the probability of occurrence of a defect in the hydraulic circuit of the.

The present invention has been made in view of the above, the second friction element, the third friction element, the fourth friction element to achieve a plurality of gear stages by combining two at the same time, the main flow path connected to the oil pump, A second solenoid valve, a third solenoid valve, a fourth solenoid valve communicating with the hydraulic source through a flow path, respectively, a second flow passage communicating the second friction element and the second solenoid valve, and the third friction element And a fourth flow passage communicating with the third solenoid valve, and a fourth flow passage communicating with the fourth friction element and the third solenoid valve, wherein the hydraulic control apparatus of the automatic transmission for a vehicle is provided in the second flow passage. A second emergency safety valve having a supply position for supplying hydraulic pressure to the second friction element connected to the second passage and a discharge position for discharging the hydraulic pressure from the second friction element; The second emergency safety valve is formed of a spool for switching a supply position and a discharge position, and pressurizing means for pressurizing the spool to the supply position side, and the spool receives hydraulic pressure supplied to the second friction element. A fourth pressure receiving surface for urging the spool in the hydraulic discharge position direction, a fifth pressure receiving surface for receiving the hydraulic pressure supplied to the third friction element and adding the spool in the hydraulic discharge position direction, and the fourth friction The sixth pressure receiving surface for receiving the hydraulic pressure supplied to the urea and for pressing the spool in the direction of the hydraulic discharge position is formed.

According to the configuration of the present invention, when two shift devices are in operation, another shift device malfunctions, and hydraulic pressure is delivered to the second, third, and fourth flow paths simultaneously, and when the hydraulic pressure becomes higher than or equal to the predetermined value, The second emergency safety valve disposed in the third flow path is switched to the discharge position where the second friction element is discharged, and a configuration that prevents the three friction elements from being engaged at the same time is necessary without arranging a switching valve in each flow path. Since the minimum number of parts can be increased, the increase in cost and the increase in the defect occurrence rate in the hydraulic circuits such as the valve stick can be suppressed low, and the hydraulic circuit can be simplified.

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, and the stator 18 of the torque converter 12 is connected to the transmission casing 22 via a one-way clutch 20. . 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 friction element, a fourth friction element 30 as a fourth friction 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 a second simple planetary gear device 40 (hereinafter referred to simply as a second gear device 40) which rotates integrally with the carrier 38 via an intermediate shaft 34 and the It is respectively connected to the first friction element 44 as the first friction element to stop 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. It is 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 and at the same time stops the rotation of the second intermediate shaft 48. It is connected to a second friction element 54 into two friction elements.

The first gear device 36 rotatably supports the first sun gear 46, the first pinion gear 56 to align with the sun gear 46, and the pinion gear 56 at the same time. It is composed of the first carrier 38, the first ring gear 50 which is engaged with the first pinion gear 56 rotatable, the second gear device 40 is the second sun gear (52), a second pinion gear (58) meshing with the sun gear (52), the second carrier (42), and the second rotatable support thereof, while rotatably supporting the pinion gear (58). The second ring gear 60 meshes with the pinion gear 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 input shaft 26 via an idler 70, and the intermediate transmission shaft ( The left end of 66 is connected to the final reduction gear 76 connected to the drive axle 74 via a differential gear arrangement 72.

In addition, as is apparent from FIG. 1, the transmission casing 22 is provided with 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 so as to contain.

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 hydraulic control device shown in FIG. 2, and the shift stage of the forward four-speed reverse first stage is achieved by the operation combination of the respective clutches and 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 second carrier 42 are fixed to form a reaction force element, and from the drive shaft 10 The driving force is 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 sun gear ( 52), the second pinion gear 58, the second ring gear 60 is transmitted to the output shaft 62, and furthermore, through the output gear 64, the intermediate transmission shaft 66, the final reduction gear 76 The first speed is achieved as transmitted from the drive axle 74 and as apparent from the first table.

Next, when the brake 44 is released and the brake 54 is engaged while the fourth friction element 30 is engaged, the rotation of the first ring gear 50 and the second sun gear 52 is stopped. To the output gear 64 via the first sun gear 46, the first carrier 38, the second carrier 42, the second ring gear 60, and the output shaft 62. Delivered, a second velocity is achieved.

Next, when the second friction element 54 is released and the third friction element 28 is engaged while the fourth friction element 30 is engaged, the first sun gear 46 and the first carrier 38 are engaged. ) Rotates integrally so that the entire first gear device 36 rotates integrally. Accordingly, the second sun gear 52 and the second carrier 42 are rotated integrally so that the second gear device 40 rotates as a whole, 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, if the fourth friction element 30 is released while the third friction element 28 is engaged while the second friction element 54 is engaged, the second sun gear 52 becomes the reaction force element and thus the driving force is reduced. It is transmitted to the second carrier 42 via the first intermediate shaft 34, and the second pinion gear 58 rotates while rotating around the outer circumference of the second sun gear 52, thereby outputting the output gear 62 through the output shaft 62. 4, a fourth speed of overdrive is achieved in which rotation of the output gear 64 is faster than 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 main flow path 88. This clutch and brake are used to engage and release the respective clutches 28, 30, 32 and brakes 44, 54 of the gear shift shown in FIG. 1 while supplying hydraulic pressure to the torque converter 12. Selectively supplied and discharged according to the operating state, mainly the pressure control valve 100, the torque converter control valve 200, the manual valve 300, the first solenoid valve 400A as the first shift device, the second shift device 2nd solenoid valve 400B as a 3rd, 3rd solenoid valve 400C as a 4th shift apparatus, 4th solenoid valve 400D as a 3rd shift apparatus, flow path pressure switching valve 500, 1st as a 1st switching means Emergency relief valve 700 is a component, each element is It is connected by a flow path.

The pressure regulating valve 100 adjusts the hydraulic pressure (flow pressure) of the main flow path 88 to a desired value corresponding to the shift stage, and has a land 106 having a pressure receiving surface 102 and a pressure receiving surface 104. ), A land 112 having a pressure receiving surface 108 and a pressure receiving surface 110 opposite to the pressure receiving surface 104, a pressure receiving surface 114 and a pressure opposite to the pressure receiving surface 110. On the land 118 having the receiving surface 116, the land 124 having the pressure receiving surface 120 and the pressure receiving surface l22 opposite the pressure receiving surface 116, and the pressure receiving surface 122. A spool formed with a land 130 having a pressure receiving surface 126 and a pressure receiving surface 128 substantially opposite, and a land 136 having a pressure receiving surface 132 opposite the pressure receiving surface 128. 138 and a spring 140 that abuts the land 136 and presses the spool 138 in the right direction in the second drawing, wherein the pressure receiving surface 108 is less than the pressure receiving surface 104. Large pressure receiving area, and The pressure receiving surface l14 has a pressure receiving area larger than the shanghai pressure receiving surface 110, and the pressure receiving surface 120 has a pressure receiving area larger than the pressure receiving surface 116, respectively. The receiving surface 122, the pressure receiving surface 126, the pressure receiving surface 128, and the pressure receiving surface 132 each have the same pressure receiving area.

The pressure receiving surface 102 has a flow passage 144 provided with an orifice 142, and the flow passage 88 has a flow path 148 provided with an orifice 146 between the pressure receiving surfaces 104, 108. A flow path 152 provided with an orifice 150 between the pressure receiving surfaces 110 and 114, and a flow path 156 provided with an orifice 154 between the pressure receiving surfaces 116 and 120, and lands 130 and 136. Between the flow path 88 via the flow path 158 and the flow path 164 communicating downstream of the orifice 162 of the flow path 160, the land 130 and the land 124 are connected to the flow path ( It communicates with the flow path 84 via 166.

The torque converter control valve 200 has a land 206 having pressure receiving surfaces 202 and 204, and a pressure receiving surface opposite to the pressure receiving surface 204 and having the same pressure receiving area as the pressure receiving surface 204. And a spring 216 contacting the land 212 to press the spool 214 in the right direction in the second direction, wherein the land 212 having the land 212 is formed. The hydraulic pressure of the oil passage 88 pressure-controlled by 100 is acted on the pressure receiving surface 202 via the oil passage 160, the oil passage 168, and the oil passage 172 provided with the orifice 170, thereby The hydraulic pressure of the oil passage 168 is adjusted to a predetermined pressure by the equilibrium, and is supplied to the torque converter 12 via the oil passage 168. The oil discharged further 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, and 310, and sets these spools in a desired position. It is arranged in the interior of the vehicle, and the position P4, which is normally used for parking, the position R for reversing, the position N for stopping, and the position D4 which enables shifting between the forward speed shift stages of the first to fourth speeds, D3 position where shifting is possible between the first and third shifting stages, two positions 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 selector lever is operated to select any one of D4, D3, 2, or L, the spool 302 is moved to the D position, and the main flow passage 88, the flow passage 314, and the solenoid valves are moved. The main flow path 316 communicating with the land 304 and the land 306 communicates with each other, and the discharge flow path 320 communicating with the flow path 144 and the discharge port 318 is connected with the land 308. It is communicated through the space between the land 310, the flow path 322, the hydraulic chamber 323 on the right side of the land 304, the first solenoid valve 400A, the second solenoid valve 400B, the first According to the on / off combination of the three solenoid valve 400C and the fourth solenoid valve 400D, the gear shifting device shown in FIG. When the selector lever is selected to the P or N position, the spool 302 is selected to the illustrated NP position, and the flow path 88 The flow path l44 passes through the space between the flow path 324, the land 308 and the land 310, and the flow path 88 and the flow path 314 pass through the space between the land 304 and the land 306. While communicating with each other, an orifice 326 is provided to connect the fifth friction element 32 to the flow path 328 and the discharge flow path 320. The space between the land 306 and the land 308, the flow path 322. In addition, the hydraulic chamber 323 is communicated, and the Jeddah flow passage 316 is also communicated to the discharge passage 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. And the gear shifting device achieves a reverse shift state (shift stage) as described later. The solenoid valve 400A is a normally open three-way valve having a coil 402a and a valve body 404a therein. And a spring 406a for pressing the valve body 404a in the open direction, and the valve body 404a is discharged to the discharge passageway 320 and the orifice 408 in the non-excited state of the coil 402a. Is installed to block communication with the first flow passage 410 connected to the first emergency safety valve 600 to be described later, and at the same time, the first flow passage 410 and the check val. A flow path 414 through which the hydraulic pressure of the main flow path 316 or the flow path 328 is communicated with each other via 412 is provided, and the valve body 404a is connected to the flow path 410 in the excited state of the coil 402a. It is comprised so that the flow path 414 may be interrupted and this flow path 410 and the discharge flow path 320 may communicate.

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. And a second flow passage 416 in which the valve body 404b is provided with a flow path 316 and an orifice 415 in a non-excited state of the coil 402b and connected to a second emergency safety valve 700 to be described later. The flow path 416 and the discharge flow path 320 are blocked and the valve body 404b is discharged to the discharge flow path 320 and the flow path 416 in the excited state of the coil 402b. It is comprised so that the flow path of the flow path 416 and the flow path 316 may be communicated with the communication of this.

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 406d for pressing the sieves 404c and 404d in the opening direction are disposed, respectively, and the discharge passage 320 is provided in the valve bodies 404c and 404d in the non-excited state of the coils 402c and 402d. ) And orifices 418, 420 are provided to block communication between the third and fourth flow passages 422, 424 connected to the fourth friction element 30 and the third friction element 28, and at the same time, 422 and 424 communicate with the flow path 316, and the valve bodies 404c and 404d block the communication between the discharge flow path 320 and the flow paths 422 and 424 in the excited state of the coils 402c and 402d. At the same time, the flow passages 422 and 424 are configured to communicate with the flow passages 316.

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 pressure switching valve 500 is for switching the flow pressure to a value corresponding to the shift stage, and the pressure receiving surface 504 and the pressure receiving surface 506 to which the hydraulic pressure of the oil passage 314 in which the orifice 502 is installed are applied. Hydraulic pressure of the pressure receiving surface 510 and the flow path 512 which oppose the land 508 having the pressure-sensitive adhesive surface 506 and the pressure receiving surface 506 and at the same time as the pressure receiving surface 506. A spool valve 518 having a land 516 having a pressure receiving surface 514, and a spring 520 contacting the pressure receiving surface 514 to press the spool valve 518 in the right direction in the second direction. When the hydraulic pressure is supplied to the flow path 314 and the hydraulic pressure is not supplied to the flow path 512, the pressure acting on the pressure receiving surface 504 is lowered to the pressing force of the spring 520 and the spool valve 518. ), The flow path 156 and the discharge port communicate with each other through the space between the lands 508 and 510. When the hydraulic pressure is not supplied to any of the oil passages 512 and 314, or when oil pressure is supplied to the oil passage 512, the pressing force of the spring 520 or the pressure force of the spring 520 is determined. 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 valve 518 is displaced in the right direction due to the pressure acting on the pressure receiving surface 514. In addition, the orifices 522 and 524 are provided in the flow path 512, and communicate with the flow path 424, and are connected to the 1st emergency safety valve 600 and the 2nd emergency safety valve 700 mentioned later.

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

In addition, the space between the land 610 and the land 616 communicates with the discharge port. Alternatively, a spring may be provided in which the hydraulic pressure is supplied to the first pressurized water column 606 to pressurize the first spool 636 to the left in the drawing. In this structure, the first pressurizing means 606 is provided. The oil passage 604 for guiding the hydraulic pressure can be omitted and the hydraulic circuit can be simplified.

Here, the first pressure receiving surfaces 614 and 618 are detection means for detecting the hydraulic pressure supplied from the oil passage 410 to the first friction element 44, and the second pressure receiving surfaces 626 and 630 are oil passages ( Detection means for detecting the hydraulic pressure supplied to the second friction element 54 at 416, 640, the third pressure receiving surface 632 detects the hydraulic pressure supplied to the third friction element 28 in the flow path 424 Each pressure receiving surface acts as a switching means for switching the position of the first spool 636.

The second emergency safety valve 700 opposes the land 706 having the pressure receiving surface 702 and the second pressurizing means 704, the second pressurizing means 704 and is larger than the second pressurizing means 704. A pressure receiving area smaller than the pressure receiving surface 710 is opposed to the land 712 and the pressure receiving surface 710 having the second pressure means 708 and the fourth pressure receiving surface 710 having a pressure receiving area. A pressure receiving surface 714 opposite to the land 718 having the fourth pressure receiving surface 714 and the pressure receiving surface 716 and the pressure receiving surface 716 and having the same pressure receiving area as the pressure receiving surface 716. A land 724 having a sixth pressure receiving surface 722, a sixth pressure receiving surface 726 opposite the pressure receiving surface 722 and having a pressure receiving area smaller than the pressure receiving surface 722; The second spool 732 is formed with a land 730 having a fifth pressure receiving surface 728, and only the oil passage is delivered to the oil passage 604 and the oil passage 416, and at the same time the oil passage 512b or the orifice ( 734 is installed in the flow path 422 When the hydraulic pressure is guided to only one side of the communicating flow path 736, the second spool 732 is held at the left end position in FIG. A flow path 640 for supplying hydraulic pressure to the 416 and the second friction element 54 is maintained in communication via the space between the land 714 and the land 712, and the hydraulic pressure to the flow paths 604 and 416. At the same time, when the hydraulic pressure is delivered to both the flow path 512 and the flow path 736, the second spool 732 is displaced to the right side of the drawing so that the flow path 640 opens the space between the land 718 and the land 724. It is configured to communicate with the discharge passage 320 and to open the second friction element 54 in an instant.

The hydraulic chamber on the right side of the land 706 communicates with the discharge port. In addition, a spring may be disposed in which the hydraulic pressure is supplied to the second pressing means 704 and 708 to press the second spool 732 in the left direction in the drawing. In this 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 fourth pressure receiving surfaces 710 and 714 are detection means for detecting the hydraulic pressure supplied from the second passage 416 to the second friction element 54. The sixth pressure receiving surfaces 722 and 726 As the detection means for detecting the hydraulic pressure supplied to the fourth friction element 30 in the flow passage 422, the fifth pressure receiving surface 728 is the hydraulic pressure supplied to the third friction element 28 in the third passage 424. Each of the pressure receiving surfaces acts as a switching means for switching the position of the second spool 732, as well as acting as detection means for detecting.

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 a certain forward shift stage is achieved. At the same time, the vehicle is made to travel by forcibly shifting to the second, third, or fourth speed.

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

When the driver sets the above-described selection lever disposed in the vehicle's cabin to the P or N position, the spool 302 of the manual valve 300, which is 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 (308) of the oil passage 324 and the manual valve 300 ( It acts on the pressure receiving surface 102 of the pressure regulator valve 100 via the space between the 310, the flow path 144. The spool 138 of the pressure regulating valve 100 is stable at a position where the pressure acting on each pressure receiving surface 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 led to the torque converter control valve 200 via the oil passage 160, and the torque converter (10) is operated by the hydraulic control action of the torque converter control valve 200 described above. 12, the working pressure of a predetermined pressure is supplied via the flow path 168. In addition, the oil pressure of the oil passage 88 is a space between the land 304 and the land 306 of the manual valve 300, the oil passage 604 of the left end of the oil pressure switching valve 500 via the oil passage 314. Is led to. 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 are in communication. 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 flow passage 322 and the discharge passage 320. The flow path 88 also communicates with the flow path 316 via the space between the land 304 and the land 306 of the manual valve 300, and the hydraulic pressure of the flow path 316 is passed through the flow path 152. Guides the space between the land 112 and the land 118 of 100. The spool l38 is formed by the forces acting on the pressure receiving surfaces 110 and 114, and the pressure receiving surfaces 104 and 108, respectively. It is stable at the position where the pressing force of the spring 140 is balanced, and a part of the oil pressure of the oil passage 158 is discharged from the oil passage 164 and the oil passage 166 so that the oil pressure of the oil passage 88 is relatively high (eg For example, 10 kg / cm ² ) is adjusted to a predetermined pressure (called a second flow 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 directed to the first solenoid valve 400A via the check valve 412 and the flow path 414.

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

In addition, when the selection lever is set to the D4 position, the above-described electronic control to achieve the first speed shift stage by combining the first friction element 44 and the fourth friction element 30 as shown in the first table. From the apparatus, 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 a non-excited state. Signals for communicating the flow path 414 and the flow path 410, the flow path 316 and the flow path 422, respectively, with only the first and third solenoid valves 400A and 400C open. The hydraulic pressure introduced to the flow path 410 is guided 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 led 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 joined at a relatively high pressure of the second flow path, 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 is engaged, each of the third solenoid valves 400C is first excited with a predetermined impact coefficient, and then the impact coefficient is gradually reduced to finally become an unexcited state. That is, when the hydraulic pressure of the flow path 638 and the flow path 422 gradually falls, 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 delivered to the oil passage 416 is the second emergency safety valve 700. The space between the land 712 and the land 718 of the land 712 is led to the second friction element 54 through the flow path 640 to engage the brake 54, and at the same time, the hydraulic pressure of the flow path 640 is It also leads to the space between the land 628 and the land 634 of the first emergency safety valve 600 via the 644. However, since the hydraulic pressure acting between the lands 616 and 622 is reduced. Of the hydraulic pressure guided into the space and acting on the pressure receiving surfaces 626 and 630, the force in the right direction is the second hydraulic pressure acting on the first pressing means 606 of the land 610. The pressing force in the left direction cannot be resisted, and the spool 636 is held in the left position in FIG. In addition, even when the second solenoid valve 400B is suddenly excited, the second friction element 54 may suddenly engage and cause a shank, so that the lamination of the solenoid valve 400B is gradually changed. The shank can be reduced by gradually raising the oil pressure of the oil passage 416 and finally making the second oil pressure.

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, the fourth friction element 30 and the third friction as shown in the first table are shown. A signal for energizing the first solenoid valve 400A to engage the element 28 and de-energizing the second to fourth solenoid valves 400B, 400C, 400D from the electronic control device. Is output.

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

Since the second solenoid valve 400B is switched from the excited state to the non-excited state, the flow path 416 communicates with the 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 flow path 316 and the flow path 424 communicate with each other, and the hydraulic pressure delivered to the flow path 424 is transferred to the third friction element 28. Guided to engage this clutch 28. The oil pressure of the oil passage 424 is also the left oil pressure chamber of the oil pressure switch valve 500 via the oil passage 512a, the oil pressure oil of the left end of the first emergency safety valve 600 and the second emergency safety via the oil passage 512b. It is also directed to the left end hydraulic chamber of the 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 path 512 and the flow path 516. The hydraulic pressure guided from the oil passage 512 to the oil passage 516 is led to the space between the land 118 and the land 124 of the pressure regulating valve 100 and acts on the pressure receiving surfaces 116, 120. The spool 138 of the pressure regulator valve 100 has a force acting on the pressure receiving surfaces 116 and 120, the pressure receiving surfaces 110 and 114, and the pressure receiving surfaces 104 and 108, and the pressing force of the spring 140. It is stable at the equilibrium position and discharges a part of the oil pressure of the oil passage 158 from the oil passages 164 and 166, and the oil pressure of the oil passage 88 is lower than the second oil pressure and higher than the first oil pressure. The pressure is adjusted to a predetermined pressure (called third flow 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. 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. Pressure is applied to the pressure receiving surfaces 722 and 726 to pressurize the spool 732 to the right, but is guided to the space between the land 706 and the land 712 via the flow path 604 to 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), the second friction element 54 is indicated as shown in the first table. And the signal for exciting the first to third solenoid valves 400A, 400B, 400C, and 400D to couple the third friction element 28 to the non-excitation of the fourth solenoid valve 400D. Output from the device. 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 non-excited 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 of the second emergency safety valve 700. The first emergency safety via the flow path 644 while being guided to the second friction element 54 via the space between the 712 and the land 718 and the flow path 640. 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 communication 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.

Since 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 ( The hydraulic pressure is also supplied to the left hydraulic pressure chamber of the 500) (the hydraulic pressure of the flow path 88 is maintained at the third hydraulic pressure pressure), the left hydraulic pressure chamber of the first emergency safety valve 600, and the left hydraulic pressure 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. The pressure receiving surface in the relation between the pressure receiving surface 632, 626, 630 and the pressure receiving surface of the pressure receiving surface 606 on which the hydraulic pressure guided to the right end hydraulic chamber of the valve 600 via the flow path 604 is applied. The hydraulic force acting on the 632, 626, and 630 resists the hydraulic force acting on the pressure receiving surface 606 to displace the spool 636 to the right of FIG. 2, and the flow path 638 discharges the flow path 320. It is configured to communicate with).

While the upshift operation from the first speed shift stage to the fourth speed shift stage has been described above, the downshift operation from only the fourth speed shift to the first speed shift stage may be performed in a completely reverse order with the upshift. Only explanation is omitted.

In addition, when the selector lever is set to the D3, D2 or L position, the shift range corresponding to the position is determined only by the command from the electronic control device, and the manual valve 300 is held at the D position so that the hydraulic circuit Since there is no change at all, the description is omitted.

Next, when the driver sets the selector lever to the R position, the spool 302 of the manual valve 300 also moves 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. The flow path 316 also communicates with the discharge flow path 320 via the right end hydraulic chamber 323. Therefore, only the hydraulic pressure guided to the space between the land 106 and the land 112 of the pressure regulating valve 100 via the flow path 148 and acting on the pressure receiving surfaces 104 and 408 is provided. By guiding, the spool 138 is stable at a position where the hydraulic force acting on the pressure receiving surface and the pressing force of the spring 140 are in equilibrium, 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 this flow path 314 is Similarly, when the shift stage of the forward is achieved, the oil pressure is led to the first and second emergency safety valves 600 and 700 via the flow path pressure switching valve 500 and the flow path 604. Guided to the fifth friction element 32, it is also applied to the check valve 412 while bringing this friction element 32 into engagement. When the selection 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 a space between the land 616 and the land 622 of the first emergency safety valve 600, and the flow path 638, leading to the first friction element 44, the brake 44 being engaged. The reverse gear stage is achieved.

Here, in the hydraulic control device shown in FIG. 2, the lowest first flow pressure when neutral, and the relatively high second flow pressure when the gear stages of the first speed and the second speed are achieved, the third speed and the third The hydraulic pressure of the flow path 88 is the third euro pressure higher than the first euro pressure when the four-speed shift stage is achieved, but relatively lower than the second euro pressure, and the highest fourth euro pressure when the reverse shift is achieved. Although this is configured to be switched, this is because the engine torque is not transmitted to the output shaft of the transmission, but the first to minimize the power loss caused by the engine driving the pump 86 at neutral, and relatively large torque is transmitted. In the gear stages of the second and second speeds, the flow pressure is relatively high and the coupling force of the coupling elements is relatively large to prevent slipping. In the gear stages of the third and fourth speeds, the transmission torque is relatively small, so the flow pressure is reduced. In a relatively low setting, and reduce the power loss to drive the pump 86, the torque transmission gear range of the cone and the backward high-pressure flow path to prevent the slip of the friction element.

In addition, by smoothly controlling the first to fourth solenoid valves 400A, 400B, 400C, and 400D, it is possible to achieve smooth shifting by controlling the oil pressure supplied to the friction element corresponding to each solenoid valve and the oil pressure discharged.

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 solenoid valve and the isoloid 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 delivered to the flow path 416 is a space between the land 712 and the land 718 of the second emergency safety valve 700. The brake 54 is guided to the second friction element 54 through the coupling, but at the same time, the land 628 and the land (628) of the first emergency safety valve 600 are passed through the flow passage 640 and the flow passage 644. Guided to the space between 634, the right direction by the hydraulic pressure acting on the pressure receiving surfaces (626, 630) in addition to the pressing force in the right direction by the hydraulic pressure acting on the pressure receiving surfaces (614, 618). Pressure to the left side by the hydraulic pressure acting on the spool 636 acting on the first pressing means 606 Against the pressure the position of the spool 636, FIG. 2 is changed over to the right. Accordingly, since the flow path 368 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, when the fourth solenoid valve 400D malfunctions and is deformed in a state where the first speed shift stage is to be achieved, the flow path 361 and the flow path 424 communicate with each other, and the hydraulic pressure is guided to the third friction element 28. At the same time, the clutch 28 is coupled to each other, and the first emergency safety valve 600 is guided to the left end hydraulic chambers of the first emergency safety valve 600 and the second emergency safety valve 700 via the flow path 512b. As described 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 the 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 first friction element 44 is released and the fourth friction element 30 and the third friction element 28. ) 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 a state where the first speed shift stage is to be achieved, only the fourth solenoid valve 400D is in a malfunction state. In addition, since the second solenoid valve 400B malfunctions and the flow path 316 and the flow path 416 communicate with each other, all the flow paths 410 and 416 communicate with each solenoid valve and each friction element 28, 30, 44, 54. , 422, 424. Then, 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 to move the spool 732 to the right direction. By pressurizing, the spool 732 is switched to the right position in the drawing 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 a 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 is greater than the pressing force in the left direction in the drawing by the hydraulic pressure acting on the first pressing means 606, the spool 636 is switched to the right position, and the flow path 638 communicates with the discharge flow path 320. 1 The friction element 44 is kept in a 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 pressure in a state in which a 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 receiving surface 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 hydraulic pressure of 410 is guided to the space between the land 616 and the land 622, the pressing force to the right of the drawing by those hydraulic pressures is shown in the drawing by the hydraulic pressure acting on the first pressing means 606. The position of the spool 636 is switched to the right side in the figure by being larger than the pressing force in the left direction. 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 hydraulic pressure of the flow path 424 is controlled by the third friction element. Guide 28 engages the clutch, and at the same time, it passes through the flow path 512b to each of the left end hydraulic chambers of the first and second emergency safety valves 600 and 700. Then, the 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, and the spool 732 by the pressing force. In the drawing of FIG. 2), the flow path 640 is sealed with the discharge flow path 320, and the second friction element 54 is released.

On the other hand, although the hydraulic pressure is delivered to the pressure receiving surface 632 of the first emergency safety valve 600 via the flow path 512b, the pressure receiving surfaces 626 and 630 are switched by the switching of the second emergency safety valve 700. Since no hydraulic pressure is delivered to the space between them, and the first solenoid valve 400A is excited, and no hydraulic pressure is 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 no hydraulic pressure is supplied to the first friction element 44 so that the brake is released. Thus, the underdrive clutch 30 and the third friction element 28 are engaged to achieve the third speed shift stage.

In addition, 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 safety valve 600 are not excited. Since the positions of the spool 732 of the emergency 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 communicating with the second friction element 54 ( 640 is connected to the flow path 320 together, the brakes 44 and 54 are released, and the fourth friction element 30 and the third friction element 28 are engaged to achieve a third speed shift stage. do.

Next, the first solenoid valve 400A 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 are not excited is to be achieved. When the excitation 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 is delivered to the space between the land 616 and the land 622 of the first emergency safety valve 600. do. At this time, since the hydraulic pressure is guided to the pressure receiving surface 632 via the flow path 512b, the position of the spool 636 is switched to the right side in the drawing in relation to the pressure receiving area with the first pressing means 606, The flow path 638 communicates with the discharge flow path 320, the hydraulic pressure is not supplied to the brake 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.

In addition, 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, since the hydraulic pressure acts on the pressure receiving surface 728 and the pressure receiving surfaces 722 and 726, 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 hydraulic pressure is not supplied to the brake 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 in the state where 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 to the right side of the drawing, the flow path 638 and the flow path 640 communicate with the discharge flow path 320 and the brakes 44 and 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 at 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, and 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.

Further, 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 clutch 30 is brought into engagement with the clutch 30, and 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. Accordingly, since 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, the position of 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 has already been switched to the right side of the drawing, and the flow passage 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, only the fourth friction element 30 and the overdrive clutch 28 are engaged, even when the second friction element 54 is released. The gear shift in the gearbox is achieved.

In the above embodiment, the first emergency safety valve 600 and the second emergency safety valve 700 are provided, and if two or more coupling elements are likely to be coupled simultaneously due to a failure of the electronic control device or solenoid valve, It is configured to leave other friction elements and release the 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 wheels of the vehicle from being suddenly fixed or completely disabled. It has the effect that it can be.

In addition, in the configuration of the above embodiment, since the solenoid valve is provided corresponding to each friction element, it is possible to control the hydraulic pressure to be supplied to the friction element and the hydraulic pressure to be discharged with high precision by controlling the impact 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 spools of the hydraulic control device is smaller than that of the conventional automatic transmission. Therefore, the probability that the solenoid valve or the spool sticks can be minimized.

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 engine rotates in a neutral state. Even if the speed increases, the oil pressure of the oil passage 88 does not increase more than necessary, and there is an effect that the occurrence of abnormal sounds can be prevented.

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

Further, in the above embodiment, the second 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. When the position of the simultaneous coupling of two or more coupling elements is prevented, the first emergency safety valve 600 is a flow path for communicating the first solenoid valve 400A and the first friction element 44, 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. A flow path communicating the second solenoid valve 400B and the second friction element 54, the third solenoid valve 400C and the fourth hemp In a flow path in which the first emergency safety valve 600 is not provided, in one flow path of the flow path communicating with the element 30 or the flow path between the fourth solenoid valve 400D and the third friction element 28. Even if it is provided, the effect similar to this embodiment 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 and the spool valve for detecting the oil pressure in each flow path communicating with the solenoid valve and the friction element are switched. Although the pressure receiving surface of the spool valve is used as a switching means, a pressure sensor serving as a detection means is provided in each of the flow paths, and on / off of an emergency safety valve made of, for example, an electronic switching valve according to the output of the sensor. Even if it is comprised so that a state may be switched, the effect similar to this embodiment is acquired.

According to the configuration of the present invention, when two shift devices are in operation, another shift device malfunctions, and the hydraulic pressure is delivered to the second, third, and fourth flow paths simultaneously, and when the hydraulic pressure becomes equal to or higher than a predetermined value, The switching valve arranged in the two flow paths is switched to the discharge position at which the hydraulic pressure of the second engagement element is discharged, and the minimum required parts without arranging the switching valve in each flow path to prevent three engagement elements from being engaged at the same time. Since the number can be achieved only by increasing the number, it is possible to suppress the occurrence of drop occurrence in the hydraulic circuits such as the increase in cost and the valve stick, and to simplify the hydraulic circuit.

Claims (2)

The second friction element 54, the third friction element 28, the fourth friction element 30, and the main flow passage 88 connected to the oil pump 86 to achieve a plurality of gear stages by combining the two simultaneously. And 316, the second solenoid valve 400B, the fourth solenoid valve 400D, the third solenoid valve 400C, and the second friction element 54, which are in communication with the hydraulic source via the main flow path, respectively. And second passages 416 and 640 communicating with the second solenoid valve 400B, third passage 424 communicating with the third friction element 28 and the fourth solenoid valve 400D, In the hydraulic control apparatus for an automatic transmission for a vehicle having a fourth flow passage 422 communicating with the fourth friction element 30 and the third solenoid valve 400C, the hydraulic flow control device is installed in the second flow passages 416 and 640. And a supply position for supplying hydraulic pressure to the second friction element connected to the second channel and a discharge position for discharging hydraulic pressure from the second friction element. And a second emergency safety valve 700. The second emergency safety valve 700 includes a spool 732 for switching between the supply position and the discharge position, and pressing means 704 and 708 for pressing the spool to the supply position. And the fourth pressure receiving surfaces 710 and 714 which receive hydraulic pressure supplied to the second friction element and pressurize the spool in the direction of the hydraulic discharge position, and the third friction element. A fifth pressure receiving surface 728 for receiving the hydraulic pressure supplied to the pressure to press the spool toward the hydraulic discharge position, and for receiving the hydraulic pressure supplied to the fourth friction element to press the spool toward the hydraulic discharge position; 6. A hydraulic pressure control device for an automatic transmission for a vehicle, characterized in that 6 pressure receiving surfaces 722, 726 are formed. 2. The pressure receiving means (704, 708) according to claim 1, wherein the pressurizing means (704, 708) is a main pressure receiving surface (704, 708) for receiving hydraulic pressure from the main flow passage (88) and pressurizing the spool to the supply position side. The effective pressure receiving area of the surface is the sum of the effective pressure receiving areas of the fourth pressure receiving surfaces 710 and 714 and the effective pressure receiving area of the fifth pressure receiving surface 728, and the fourth pressure receiving surface 710. , 714, the sum of the effective pressure receiving area of the sixth pressure receiving surface 722, 726, and the effective pressure receiving area of the fifth pressure receiving surface 728, and the sixth pressure receiving surface 722. 726 is greater than the sum of the effective pressure receiving areas, and each of the fourth pressure receiving surfaces 710 and 714, the fifth pressure receiving surface 728, and the sixth pressure receiving surfaces 722 and 726 A hydraulic control device for an automatic transmission for a vehicle, characterized in that it is formed smaller than the sum of the areas.

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