JP4366653B2 - Hydraulic control device for automatic transmission - Google Patents

Description

  The present invention relates to a hydraulic control device for an automatic transmission.

Conventionally, in order to improve the fuel efficiency of a vehicle equipped with an automatic transmission, a lockup that directly connects an output shaft from the engine and an input shaft of the automatic transmission has been adopted. The lockup is used at a high speed stage where the traveling of the vehicle is stabilized among a plurality of shift stages.
In recent years, in order to further improve fuel efficiency, lock-up slip control that locks up at low speeds and maintains the running performance by slightly sliding the lock-up clutch in low speed ranges has been adopted. Therefore, it is necessary to add a dedicated electromagnetic valve or spool valve to the friction engagement element used at the low speed stage. As a result, the number of parts is increased and the size of the physique is increased.

  Further, in the automatic transmission, when the forward range is selected by the shift lever and the vehicle is moving forward, it is necessary to prevent a sudden shift to the reverse stage even if the reverse range is selected by the shift lever. Therefore, the automatic transmission has conventionally been provided with a reverse prohibiting means for prohibiting the shift to the reverse gear, or an electromagnetic valve for smoothly shifting the friction engagement element to the reverse (see Patent Document 1). These also cause an increase in the number of parts and an increase in the size of the physique. Therefore, in the invention disclosed in Patent Document 2, an orifice is installed to reduce the number of solenoid valves.

JP-A-6-58405 Japanese Patent Laid-Open No. 2002-22002

As shown in FIG. 3 , in the invention disclosed in Patent Document 2, a reverse clutch (R / C, “B1” in Patent Document 2) 501, which is a friction engagement element that forms a reverse gear, is provided on the hydraulic pressure input side. An orifice 502 and a check valve 503 are installed. In the prior art shown in FIG. 3 , the same components as those in the embodiment of the present invention shown in FIG. There is also an automatic transmission in which an accumulator is installed on the hydraulic pressure input side of R / C instead of the orifice 502 and the check valve 503. These adjust the hydraulic pressure input to the R / C 501 to prevent the shift to the reverse gear during forward travel.

  However, when the orifice 502 and the check valve 503 are installed, and when the accumulator is installed, the diameter of the orifice 502, the valve opening pressure of the check valve 503, and the operating pressure of the accumulator are adjusted according to the traveling region of the vehicle. There is a need. In order to adjust these according to all the travel areas of the vehicle in which the automatic transmission is mounted, there is a problem that a great number of man-hours are required.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a control device for an automatic transmission that achieves lock-up when moving forward at a low speed with a simple structure and has a high degree of freedom in control.

In the hydraulic control device for the automatic transmission according to claim 1 Symbol placement of the present invention, by way of the Ma Nyuarubarubu, switching the output side of the solenoid valve to the lockup hydraulic circuit or a hydraulic circuit pressure regulating valve of the reverse clutch. That is, the single solenoid valve controls the lockup hydraulic circuit and the reverse clutch. Therefore, the number of parts can be reduced and the structure can be simplified. When the forward range is selected by the shift lever, connected to the lock-up hydraulic circuit portion on the output side of the solenoid valve via a Ma Nyuarubarubu. As a result, the hydraulic pressure is supplied to the lockup hydraulic circuit unit during forward movement. Therefore, it is possible to achieve lockup during advance at low speed. Further, when the reverse range is selected by the shift lever, via Ma Nyuarubarubu connected to the hydraulic circuit of the pressure regulating valve of the reverse clutch of the plurality of frictional engagement elements on the output side of the electromagnetic valve. As a result, the hydraulic circuit during forward or reverse travel is switched by the manual valve, and both states can be controlled by the electromagnetic valve. Therefore, for example, an orifice, a check valve or an accumulator for controlling the supply of hydraulic pressure to the reverse clutch is not required. Therefore, detailed adjustment is unnecessary, and the degree of freedom in control can be increased.

  In the hydraulic control device for an automatic transmission according to the present invention, the solenoid valve can control the pressure regulation state of the friction engagement element by an electric signal. Therefore, when the vehicle is moving forward, the hydraulic pressure is not applied to the reverse friction engagement element by the electric signal. Thus, even if the shift lever is switched to the reverse range when the vehicle moves forward, the reverse pressure adjusting circuit does not operate if the electric signal is controlled so as not to generate pressure on the friction engagement element. As a result, the hydraulic pressure is supplied to the reverse clutch, and the reverse clutch is not engaged. Therefore, damage to the friction engagement element can be prevented.

Hereinafter, a plurality of embodiments to which the present invention is applied will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows a hydraulic control device for an automatic transmission according to a first embodiment of the present invention. Reverse clutch (R / C) 1 as reverse clutch, overdrive clutch (H / C) 2, 2-4 brake (2-4 / B) 3, low clutch (L / C) 4, low reverse brake ( LR / B) 5 and transfer clutch (TRF) 6 are friction engagement elements that are engaged or released by hydraulic pressure to form a gear stage.

  The hydraulic pump 40 sucks hydraulic oil from the oil pan 41 and supplies the hydraulic oil to the communication path 100. The electromagnetic valve 44 receives a command value from a control device (ECU; Electric Control Unit) (not shown) and generates a command pressure corresponding to the command value. The line pressure control valve 42 cooperates with the secondary valve 43 to generate a line pressure serving as an original pressure of the hydraulic pressure supplied to each friction element and the lockup clutch 51 based on the command pressure of the electromagnetic valve 44.

  Specifically, the line pressure control valve 42 is connected to the electromagnetic valve 44 by a communication passage 115 that transmits the command pressure of the electromagnetic valve 44. The line pressure control valve 42 is connected to communication passages 101 and 102 branched from the communication passage 100. The line pressure control valve 42 discharges part of the hydraulic oil introduced from the communication path 101 to the communication path 103 connected to the secondary valve 43 based on the command pressure of the electromagnetic valve 44 and the hydraulic pressure of the communication path 102. Thereby, the hydraulic pressure of the communication path 100 is controlled as a line pressure. The communication passages 110, 120, 127, 140, 170 branched from the line pressure communication passage 100 are connected to the pressure reduction control valve 45, the manual valve 38, the clutch pressure control valve 26, the clutch pressure control valve 32, and the fail safe valve 14, respectively. is doing.

  The pressure reduction control valve 45 uses the output pressure from the communication path 111 as a feedback pressure. In the pressure-reducing control valve 45, a force due to the feedback pressure is applied to the spool 49 biased by the spring 48 in a direction opposite to the biasing force of the spring 48 so that the feedback pressure acts in the direction of decreasing the output pressure. . Thereby, the pressure reduction control valve 45 reduces the line pressure transmitted through the communication passage 110 on the input side, and generates an output pressure that does not exceed the line pressure. This output pressure is called modulated pressure. The pressure reduction control valve 45 is connected to the electromagnetic valve 44 by a communication path 111 for transmitting a modulated pressure and a communication path 116 branched from the communication path 111.

  The manual valve 38 is connected via a link to a shift lever 39 operated by the driver. The manual valve 38 moves according to the operation of the shift lever 39 to switch the passage communicating with the communication passages 122, 123, 128, 129 to the communication passage 120 for line pressure or the drain passage 121 for drain pressure. The communication paths 195 and 196 branched from the communication path 122 are connected to R / C1 and LR / B5, respectively. The communication passages 124, 125, and 126 branched from the communication passage 123 are connected to the clutch pressure control valves 10, 16, and 20, respectively. The manual valve 38 has four switching positions “P, R, N, D” corresponding to the range of the shift lever. “P” and “N” are the same communication pattern. As shown in FIG. 2, a combination of engagement and release of each friction element is determined in advance according to each shift speed, and a shift command is output from the ECU according to this combination. In FIG. 2, the gear position indicated by R corresponds to the R range. The clutch pressure control valve 10, the clutch pressure control valve 16, the clutch pressure control valve 20, the clutch pressure control valve 26, and the clutch pressure control valve 32 are H / C2, 2-4 / B3 other than R / C1, respectively, together with an electromagnetic valve. The hydraulic pressure applied to L / C4, LR / B5 and TRF6 is regulated.

  The fail safe valve 22 switches the passage communicating with the communication passage 172 to either the communication passage 179 or the drain passage 178 branched from the communication passage 176 based on the hydraulic pressure of the communication passage 187 branched from the communication passage 173. The fail safe valve 14 switches the passage communicating with the communication passage 174 to either the communication passage 173 or the drain passage 190 based on the hydraulic pressure of the communication passages 170 and 172 and the hydraulic pressure of the communication passage 171 branched from the communication passage 175. . The failsafe valve 24 switches the passage communicating with the communication passage 189 to either the communication passage 188 or the drain passage 192 based on the hydraulic pressure of the communication passages 183 and 185 branched from the communication passages 175 and 174, respectively. The high pressure selection valve 29 selects the high pressure side of the communication passages 189 and 196 to communicate with the LR / B5.

The lockup clutch 51 connects or disconnects the output shaft on the engine side and the input shaft on the automatic transmission side. The lockup clutch 51 bypasses the torque converter 50 when connected and transmits power from the engine to the automatic transmission. The lockup relay valve 54 is connected to the manual valve 38 via the communication path 129 . Lock-up clutch 51, the lock-up clutch control valve 52 and the lock-up relay valve 54 constitutes a lockup hydraulic circuit portion 55.

Depending on the driving range selected by the sheet shift lever 39, the hydraulic circuit from the solenoid valve 70 lockup hydraulic circuit portion 55 or to the R / C1 or LR / B5, is switched. When forward range or "D range" is selected by the shift lever 39 connects the output side of the solenoid valve 70 to the lockup hydraulic circuit portion 55 via the Ma Nyuarubarubu 38. That is, the electromagnetic valve 70 connects the communication path 301 connecting the pressure reducing control valve 45 and the electromagnetic valve 70 to the communication path 302 connecting the electromagnetic valve 70 and the manual valve 38. At the same time, the manual valve 38 connects the communication path 302 and the communication path 129 in the D range. As a result, the communication path 302 on the output side of the electromagnetic valve 70 is connected to the lockup hydraulic circuit unit 55.

Therefore , when the “D range” is selected by the shift lever 39, the lockup hydraulic circuit 55 is supplied with hydraulic pressure. As a result, the hydraulic pressure required for engaging the lockup clutch 51 is supplied to the lockup hydraulic circuit 55 regardless of the speed of the vehicle. As a result, the lockup clutch 51 can be engaged even at a low speed such as the first speed or the second speed.

On the other hand, when the reverse range, or "R range" is selected by the shift lever 39 is the output side of the solenoid valve 70 in the hydraulic circuit of the pressure regulating valve 310 of the R / C1 and LR / B5 via Ma Nyuarubarubu 38 Connected to the communication path 128 . That is, the electromagnetic valve 70 connects the communication path 301 connecting the pressure reducing control valve 45 and the electromagnetic valve 70 to the communication path 302 connecting the electromagnetic valve 70 and the manual valve 38. At the same time, the manual valve 38 connects the communication path 302 and the communication path 128 in the R range. The communication path 128 is connected to the pressure regulating valve 310 and is connected to the communication path 195 and the communication path 196. The pressure regulating valve 310 is a pressure regulating valve for a reverse clutch that controls the hydraulic pressure supplied to the R / C 1. By hydraulic pressure that is output to the communication path 128 via the manual valve 38, hydraulic pressure is outputted from the pressure regulating valve 310 via the communicating passage 195 or communication path 196 to the R / C1 or LR / B5. As a result, the communication path 302 on the output side of the electromagnetic valve 70 is connected to the communication path 128 .

Therefore , when the “R range” is selected by the shift lever 39, hydraulic pressure is supplied to R / C1 and LR / B5. As a result, the hydraulic pressure required for the engagement of R / C1 is supplied when the vehicle moves backward.
On the other hand, as shown in FIG. 2, the reverse range, that is, the “R range” is not formed unless the R / C 1 is engaged. Therefore, when the vehicle is moving forward at a certain speed or higher, the operation of the electromagnetic valve 70 is stopped so that the R / C1 is not engaged. That is, when the vehicle is moving forward at a certain speed or higher, the ECU does not output a signal for switching to the electromagnetic valve 70. Accordingly, the shift lever 39 during advancement of the vehicle is also switched from the "D range" to "R" range, not connected to the output side and the manual valve 38 of the electric solenoid valve 70. Therefore, the hydraulic pressure output from the electromagnetic valve 70 is not supplied to the R / C 1 via the manual valve 38. As a result, R / C1 does not engage.

As described above, in the first embodiment, it switches the output side of the solenoid valve 70 to the lockup hydraulic circuit section 55 or the R / C1 via the Ma Nyuarubarubu 38. As a result, the hydraulic circuit during forward travel or reverse travel is switched by the single solenoid valve 70. Further, the hydraulic circuit during forward-movement or backward is switched by Ma Nyuarubarubu 38. Therefore, a complicated mechanism and a hydraulic circuit are not required, the number of parts can be reduced, and the structure can be simplified.

In the first embodiment, when “D range” is selected by the shift lever 39, the output side of the electromagnetic valve 70 is connected to the lockup hydraulic circuit 55. Therefore, the hydraulic pressure is always supplied to the lockup hydraulic circuit 55 when the vehicle moves forward. Therefore, when the vehicle is moving forward, the lockup clutch 51 can be operated regardless of the gear position. When “R range” is selected by the shift lever 39, the output side of the solenoid valve 70 is connected to R / C1. Therefore, when the vehicle is moving backward, the hydraulic pressure is supplied to the R / C 1 without requiring an orifice, a check valve or an accumulator, for example. Therefore, the engagement of R / C1 can be achieved without requiring detailed adjustment, and the degree of freedom of control can be increased.

  Furthermore, in the first embodiment, the electromagnetic valve 70 is electrically controlled by an ECU (not shown). Therefore, the traveling range selected by the shift lever 39 and the electromagnetic valve 70 can be controlled independently. As a result, even if the shift lever 39 is switched from the “D range” to the “R range” while the vehicle is running, the ECU does not operate the electromagnetic valve 70 when the vehicle is at a predetermined speed or higher. Therefore, the hydraulic pressure is not supplied to the R / C 1 when the vehicle moves forward, and the engagement of the R / C 1 at an inappropriate time is prevented. Therefore, the engagement of R / C1 when the vehicle moves forward is electrically prevented, and damage to members constituting R / C1 can be prevented.

1 is a schematic diagram showing a hydraulic circuit of a hydraulic control device for an automatic transmission according to a first embodiment of the present invention. It is a figure which shows the engagement table | surface of the automatic transmission by 1st Embodiment of this invention. It is a schematic diagram which shows the hydraulic circuit of the hydraulic control apparatus of the conventional automatic transmission.

Explanation of symbols

1 R / C (reverse clutch, friction engagement element), 2 H / C (friction engagement element), 3 2-4 / B (friction engagement element), 4 L / C (friction engagement element), 5 LR / B (friction engagement element), 38 manual valve, 39 shift lever, 51 lock-up clutch, 55 lock-up hydraulic circuit, 70 solenoid valve , 310 pressure regulating valve

Claims (1)

Lock lockup hydraulic circuit oil pressure is supplied to control the intermittence of click-up clutch (51) and (55),
A plurality of friction engagement elements (1, 5) including a reverse clutch (1) ;
An electromagnetic valve (70) for outputting hydraulic pressure to the lockup hydraulic circuit (55) and the plurality of friction engagement elements (1, 5) ;
A manual valve (38) interlocked with a shift lever (39) capable of selecting a forward range and a reverse range;
It said shift lever (39) by the forward range is output side to the lock-up hydraulic circuit portion of the manual valve when it is selected the solenoid valve via a (38) (70) (55) and connects the, the manual pressure regulating valve of the valve the solenoid valve via (38) said reverse clutch the output side (70) (1) when the reverse range is selected by said shift lever (39) of the (310) A hydraulic control device for an automatic transmission, which is connected to a hydraulic circuit (128) .

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