JP2016014402A - Hydraulic control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic control device capable of achieving fuel consumption performance equal to a conventional one while using control elements in common to reduce the number of control elements.SOLUTION: A solenoid pressure selected by a maximum pressure selector valve is used as a control original pressure, and an oil path for the output pressure of a solenoid valve used in common is switched over by a manual valve and an electromagnetic valve. When an excess pressure higher than a common region pressure is output from the solenoid valve during failure, an oil path for a shift control solenoid valve is switched over by a spool valve to establish a predetermined shift stage, and a hydraulic pressure to be supplied to an engagement element to be used during reverse travel is switched over from a solenoid control pressure into a reverse-travel line pressure by the electromagnetic valve.

Description

  The present invention relates to a hydraulic control device that controls a stepped automatic transmission mounted on a vehicle.

  A transmission is mounted on the vehicle in order to shift the output rotation from the internal combustion engine mounted on the vehicle in accordance with the traveling state. One type of transmission is a stepped automatic transmission that uses a planetary gear mechanism to synchronize the rotation of its constituent elements with a clutch or engage with a brake to shift gears.

  A hydraulic control device is used to control the stepped automatic transmission. The hydraulic control device includes a hydraulic circuit including elements such as a linear solenoid valve, a solenoid valve, and a spool valve. For example, the hydraulic circuit illustrated in FIG. 7 is a schematic diagram of a hydraulic circuit diagram of a stepped automatic transmission capable of configuring a forward gear 1st to 4th gear, a reverse gear, and an engine brake gear using a planetary gear mechanism. is there.

  In the hydraulic circuit diagram shown in FIG. 7, there are five linear solenoid valves (reference numerals 20, 22, 24, 26, and 28), one ON / OFF switching solenoid valve (reference numeral 30), and nine spool valves (reference numeral 33). , 34, 36, 38, 42, 44, 46, 48, 47). A linear solenoid valve is more expensive than a solenoid valve or a spool valve, and has a large volume and weight. For this reason, if many linear solenoid valves are used, parts cost will increase. In addition, the volume and weight of the hydraulic control device increase, and there is a problem that the mountability and lightness are impaired.

  Although it is possible to reduce the number of linear solenoid valves to be used and configure a hydraulic circuit that can configure the same gear stage, performance and quality such as low fuel consumption performance and shift shock There is a problem that will decrease.

  The present invention was created in view of the above problems, and an object thereof is to provide a hydraulic control device for a stepped automatic transmission capable of reducing the number of linear solenoid valves to be used while maintaining low fuel consumption performance and quality. To do.

The present invention provides a hydraulic control device for a stepped automatic transmission for a vehicle. In this hydraulic control device,
A plurality of shift control solenoid valves;
An output control pressure of the shift control solenoid valve is introduced, a maximum pressure selection valve that selects and outputs a maximum hydraulic pressure from the output control pressure; and
A manual valve that switches the oil path by a shift operation,
It has a normally closed solenoid valve,
A power transmission element constituting the planetary gear mechanism;
A plurality of engagement elements that lock or synchronize rotation of the power transmission element,
The control source pressure is regulated by the output pressure of the maximum pressure selection valve,
The oil passage is switched by the manual valve and the normally closed electromagnetic valve, and the engagement element to which the output pressure of the shift control solenoid valve is supplied is changed.

  As will be described in detail later, low fuel consumption performance is realized by adjusting the control source pressure to the minimum necessary value as described above. Further, by switching the oil passage by the manual valve and changing the engagement element to which the output pressure of the shift control solenoid valve is supplied, a plurality of engagement elements are controlled by one shift control solenoid valve. By reducing the number of solenoid valves to be used, it is possible to reduce the parts cost and the volume and weight of the hydraulic control device.

In the hydraulic control device of the present invention,
A solenoid valve capable of outputting a surplus pressure higher than the normal range pressure;
A spool valve that operates by surplus pressure of the solenoid valve,
When surplus pressure higher than the normal pressure is output from the solenoid valve,
With the spool valve,
The oil passage of the shift control solenoid valve is switched,
A predetermined gear position is established at the time of failure.

  As will be described in detail later, even if the solenoid valve for speed change control and the electronic control means for controlling the stepped automatic transmission have failed (failed), the third speed can be achieved by configuring a fail-safe circuit. Once established, limp home is possible.

In the hydraulic control device of the present invention,
The normally closed solenoid valve switches the hydraulic pressure supplied to the engagement element used during reverse operation from the output control pressure to the reverse line pressure.
The hydraulic control device according to claim 1, wherein

  As will be described in detail later, even when a large engine torque is input to the stepped automatic transmission during reverse, the engagement is prevented by preventing slippage of the engagement element used during reverse, and the engagement element is damaged. Can be prevented.

  According to the hydraulic control device of the present invention, when the number of linear solenoid valves to be used is reduced, a limp home can be realized by configuring a fail-safe circuit while reducing the cost and reducing the volume and weight of the hydraulic control device. In addition, it is possible to maintain low fuel consumption performance and shift performance.

  Here, the engagement element is a friction engagement element that can be engaged and released by hydraulic control, such as a wet multi-plate clutch and a brake.

  In addition, the limp home is equipped to safely return the occupant while preventing damage to other parts such as the internal combustion engine and the automatic transmission of the failed vehicle when the automatic transmission fails. .

It is the schematic of the hydraulic circuit of the hydraulic control apparatus which concerns on one Embodiment of this invention. It is the schematic of the hydraulic circuit for demonstrating the switching of the oil path in the hydraulic control apparatus which concerns on one Embodiment of this invention. It is the schematic of the hydraulic circuit for demonstrating the structure of the fail safe circuit in the hydraulic control apparatus which concerns on one Embodiment of this invention. It is the schematic of the hydraulic circuit for demonstrating the switching of the control hydraulic pressure at the time of reverse | retreat in the hydraulic control apparatus concerning one Embodiment of this invention. 1 is a skeleton diagram schematically showing a structure of a main part of a stepped automatic transmission controlled by a hydraulic control device according to an embodiment of the present invention and a conventional hydraulic control device. 5 is a chart showing elements engaged at each gear stage in a hydraulic control device according to an embodiment of the present invention and a hydraulic circuit of a conventional hydraulic control device. It is the schematic of the hydraulic circuit of the conventional hydraulic control apparatus. FIG. 8A is a chart showing control elements used at each gear stage. FIG. 8A shows control elements used at each gear stage in the hydraulic control device according to the embodiment of the present invention, and FIG. Indicates control elements used at each gear position in the conventional hydraulic control device.

  As shown in FIG. 1 which is a schematic diagram of a hydraulic circuit 62 of a hydraulic control apparatus 60 according to an embodiment of the present invention, the hydraulic circuit 62 includes four linear solenoid valves (reference numerals 20, 22, 24, 26), One ON / OFF switching solenoid valve (reference numeral 30) and ten spool valves (reference numerals 32a, 32b, 34, 36, 38, 42, 44, 46, 47, 48) are used. Here, the maximum pressure selection valve 32 includes spool valves 32a and 32b.

  As described above, the conventional hydraulic circuit 162 illustrated in FIG. 7 can configure the forward gear 1st to 4th gear, the reverse gear, and the engine brake gear using a planetary gear mechanism. In this hydraulic circuit 162, five linear solenoid valves, one ON / OFF switching electromagnetic valve, and nine spool valves are used.

  Similar to the conventional hydraulic circuit 162, the hydraulic circuit 62 of the hydraulic control device 60 according to one embodiment of the present invention uses a planetary gear mechanism to move forward speed 1st to 4th speed, reverse speed, and engine brake speed. And can be established. As described above, this hydraulic circuit 62 uses four linear solenoid valves, one ON / OFF switching electromagnetic valve, and ten spool valves.

  In other words, the hydraulic circuit 62 of the hydraulic control device 60 according to an embodiment of the present invention is configured with two spool valves instead of the reverse control valve 33, eliminating the line pressure control solenoid valve 28 from the conventional hydraulic circuit 162. A maximum pressure selection valve 32 is provided.

  In other words, by eliminating the line pressure control solenoid valve 28, which is an expensive linear solenoid valve, and adding one inexpensive spool valve, it is possible to reduce costs and reduce the volume and weight of the hydraulic control device. The same gear is realized.

  Below, the operation | movement at the time of the speed change of the hydraulic circuit 62 is demonstrated in detail, referring FIG.1, FIG.5, FIG.6-FIG.

  As shown in FIG. 5, which is a skeleton diagram schematically showing the structure of a main part of a stepped automatic transmission controlled by a hydraulic control device 60 according to an embodiment of the present invention and a conventional hydraulic control device 160. What is controlled by the hydraulic circuit 62 of the hydraulic control device 60 according to one embodiment of the invention and the hydraulic circuit 162 of the conventional hydraulic control device 160 of FIG. 7 is generally the sun gear, pinion gear, carrier, and ring gear. This is a stepped automatic transmission using the planetary gear mechanism 70 configured.

  The planetary gear mechanism 70 is provided with a brake that locks the rotation of its components and a clutch that synchronizes the rotations of the components. More specifically, the planetary gear mechanism 70 includes a B1 brake 11, a B2 brake 12, a C1 clutch 15, a C2 clutch 16, a C3 clutch 17, and a one-way clutch. The one-way clutch does not require hydraulic control, allows rotation in one direction, and locks rotation in the other direction.

  FIG. 6 is a chart showing elements that are engaged at each speed in the hydraulic circuit 62 of the hydraulic control device 60 according to the embodiment of the present invention and the hydraulic circuit 162 of the conventional hydraulic control device 160. As an example, when traveling at the second speed, the B1 brake 11 and the C2 clutch 16 are controlled to be engaged. When shifting from the 2nd speed to the 3rd speed, control is performed to engage the C3 clutch 17 while releasing the B1 brake 11 while the C2 clutch 16 is engaged.

  FIG. 8 is a chart showing the control elements used at each gear stage. FIG. 8A shows control elements used at each shift stage in the hydraulic control apparatus 60 according to one embodiment of the present invention, and FIG. 8B shows the control elements used at each shift stage in the conventional hydraulic control apparatus 160. Indicates the control element used.

  As shown in FIG. 8 (b), in the conventional hydraulic control device 160, the line pressure control solenoid valve 28 in FIG. 7 is used for forward travel between the 1st to 4th speeds and the engine brake range and during reverse travel. The control source pressure PL is controlled. More specifically, the brakes and clutches to be engaged are changed at each gear stage shown in FIG. At this time, the hydraulic pressure required to control the engagement of each brake and clutch and maintain the engaged state varies depending on the gear position.

  For example, when traveling at the second speed, the B1 brake 11 and the C2 clutch 16 are engaged as shown in FIG. At this time, the hydraulic pressure for maintaining the B1 brake 11 in the engaged state is different from the hydraulic pressure P for maintaining the C2 clutch 16 in the engaged state.

  The control source pressure PL can be adjusted to the higher one of the required control hydraulic pressures among the engagement pressure of the B1 brake 11 and the engagement pressure of the C2 clutch 16 by the line pressure control solenoid valve 28 of FIG. Controlled by value. In other words, the control source pressure PL is any of the output pressure PL1 of the SL1 solenoid valve 20 that controls the brake pressure, the output pressure PL2 of the SL2 solenoid valve 22 that controls the clutch pressure, and the output pressure PL3 of the SL3 solenoid valve 24. Or a plurality of values that can be generated and supplied to each clutch or brake.

  The output pressure PL1 of the SL1 solenoid valve 20, the output pressure PL2 of the SL2 solenoid valve 22, and the output pressure PL3 of the SL3 solenoid valve 24 are adjusted (reduced) by the control source pressure PL by the control of each solenoid valve. Hydraulic.

<< Control pressure adjustment method in conventional hydraulic control system >>
With reference to FIG. 7, a method of adjusting the control source pressure PL in the hydraulic circuit 162 of the conventional hydraulic control device 160 will be described. The pressure Pp generated by the oil pump 55 shown in FIG. 7 is adjusted to the regulator pressure Pr by the primary regulator valve 44 and supplied to the line pressure control solenoid valve 28. The regulator pressure Pr supplied to the line pressure control solenoid valve 28 is adjusted to the line pressure PL and output by a line pressure control solenoid valve 28 controlled by an electronic control means (not shown).

  As described above, the control source pressure PL in the hydraulic circuit 162 of the conventional hydraulic control device 160 is always controlled to the minimum necessary value. The hydraulic pressure used for shift control of an automatic transmission (not shown) is generated by the hydraulic pressure generating means shown in FIG. Since the oil pump 55 is driven by an internal combustion engine (not shown) (hereinafter also referred to as “engine”), the load of the engine that drives the pump 55 is reduced by reducing the generated hydraulic pressure to the minimum necessary. Fuel consumption is improved.

<< Method for Regulating Control Source Pressure in Hydraulic Control Device of the Present Invention >>
In the present invention, the line pressure control solenoid valve 28 is eliminated. Therefore, the line pressure is set to the minimum necessary value as follows.

As shown in FIG. 1, in the hydraulic circuit 62 of the present invention, the pressure Pp generated by the oil pump 55 is regulated to the regulator pressure Pr by the primary regulator valve 44, and the manual valve 40
Is supplied to any one of the SL2 solenoid valve 22 and the SL3 solenoid valve 24, or to a plurality of solenoid valves necessary for establishing a desired gear position.

  Further, the regulator pressure Pr is directly supplied from the primary regulator valve 44 to the SL1 solenoid valve 20 and the ON / OFF solenoid valve 30.

  The regulator pressure Pr supplied to one or more of the SL2 solenoid valve 22, the SL3 solenoid valve 24, and the SL1 solenoid valve 20 is supplied to the clutch of the hydraulic pressure supply destination at each solenoid valve 22, 24, 20. And pressures PL2, PL3, and PL1 at which the brake can be engaged are regulated and output.

  The clutches and brakes supplied with the hydraulic pressure as described above, that is, any one or more of the B1 brake 11, B2 brake 12, C1 clutch 15, C2 clutch 16, and C3 clutch 17 shown in FIG. 1 are engaged. Further, the clutches and brakes for which the supply of hydraulic pressure has been stopped are released, and a gear shift of a stepped automatic transmission (not shown) is performed.

  As shown in FIG. 1, the control output pressure supplied to the clutch or brake after being regulated by any one or more of the SL2 solenoid valve 22, the SL3 solenoid valve 24, and the SL1 solenoid valve 20, The maximum pressure selection valve 32 is also introduced.

  More specifically, one of the control output pressure PL1 of the SL1 solenoid valve 20 that controls the brake pressure, the control output pressure PL2 of the SL2 solenoid valve 22 that controls the clutch pressure, and the control output pressure PL3 of the SL3 solenoid valve 24. Or a plurality are introduced into the maximum pressure selection valve 32.

  The output pressures PL1, PL2, and PL3 are respectively adjusted to pressures at which a clutch or a brake that supplies hydraulic pressure can be engaged. Further, as shown in FIG. 1, the PL 2 is introduced into the maximum pressure selection valve 32 through a shift valve 42 that is normally maintained in the upper half state of FIG. 1.

  The maximum pressure selection valve 32 is configured to select and output the maximum pressure from the introduced pressures according to the hydraulic pressure balance. Thus, the maximum pressure is output from the maximum pressure selection valve 32 among the control output pressure PL1 of the SL1 solenoid valve 20, the control output pressure PL2 of the SL2 silenoid valve 22, and the control output pressure PL3 of the SL3 solenoid valve 24. Is done.

  In the present invention, the pressure PLx output from the maximum pressure selection valve 32 is used as the control source pressure. In other words, among the control pressures adjusted so that the clutch and the brake can be engaged, the maximum control pressure is output as the control source pressure PLx. This control source pressure PLx is a minimum pressure necessary for configuring a desired shift speed, and is substantially equal to the control source pressure PL in the conventional hydraulic control device 160.

  As described above, in the hydraulic control device 60 of the present invention that does not include the line pressure control solenoid valve 28, the control source pressure PLx can be made substantially equal to the conventional control source pressure PL, and low fuel consumption performance can be achieved.

  More specifically, as shown in FIG. 1, the control source pressure PLx is introduced into the primary regulator valve 44 and the secondary regulator valve 46 in the same manner as the control source pressure PL in FIG. 7, and the oil introduced into the primary regulator valve 44. The hydraulic pressure Pp generated by the pump is appropriately adjusted to a regulator pressure Pr that is a line pressure at the time of forward movement. Further, the regulator pressure Pr introduced into the secondary regulator valve 46 is appropriately adjusted to a direct connection control original pressure Pt used for direct connection control of the torque converter 50.

  As described above, it is possible to perform the same shift control as before while suppressing the regulator pressure Pr, which is the line pressure at the time of forward movement, to the necessary minimum value by using the control source pressure PLx in all the first to fourth gears. It is possible to achieve the same low fuel consumption performance as before.

<Switching of oil passage for control pressure output from solenoid valve for shift control>
In the present invention, the oil passage is switched by the manual valve 40 and the ON / OFF solenoid valve 30 in the normal D range and in the engine brake range, and the SL1 solenoid valve 20 which is a shift control solenoid valve is used. The engagement element to which the output pressure is supplied is changed. Thereby, the B1 brake 11 and the B2 brake 12 which are engaging elements are controlled by the SL1 solenoid valve 20.

  FIG. 2 is a schematic diagram of a hydraulic circuit for explaining switching of an oil passage in the hydraulic control apparatus according to the embodiment of the present invention, and FIG. The switching of the oil passage with time will be described in detail.

  In a normal D range, a vehicle (not shown) travels with a speed change between 1st speed and 4th speed. In FIG. 6, the engagement elements necessary for configuring the first to fourth speeds are the B1 brake 11, the C2 clutch 16, and the C3 clutch 17.

  Further, the engagement elements necessary for constituting the engine brake range are the B2 brake 12 and the C2 clutch 16. In the hydraulic circuit 62 shown in FIG. 2, the B1 brake 11 which is an engagement element necessary for configuring the first to fourth speeds, and the B2 brake 12 which is an engagement element necessary for configuring the engine brake range, Is controlled by one solenoid valve, namely the SL1 solenoid valve 20. For this purpose, the oil passage is switched.

  When the vehicle travels in the normal D range, that is, between the first speed and the fourth speed, it is necessary to control the engagement and release of the B1 brake 11 by the SL1 solenoid valve 20, as described above.

  In the above case, the B1 relay valve 36 in FIG. 2 is energized by the regulator pressure Pr supplied from the manual valve 40 to the left end of FIG. 2 and is in the state shown in the lower half of FIG.

  As a result, the fail-safe valve 34 is also energized by being supplied with the regulator pressure Pr that has passed through the B1 relay valve 36 to the left end of the drawing, and is in the lower half of the figure. As a result, the control pressure PL1 regulated and output by the SL1 solenoid valve 20 passes through the B1 relay valve 36 and the fail-safe valve 34, and is supplied to the B1 brake 11.

  When the shift operation is performed to the engine brake range, the regulator pressure Pr adjusted by the primary regulator valve 44 is supplied to the right side of the B1 relay valve 36 as viewed in the drawing. Further, the regulator pressure Pr supplied to the left end of the B1 relay valve 36 is cut off.

  As a result, the B1 relay valve 36 is energized by the regulator pressure Pr and the spring 36a disposed on the right side of the B1 relay valve 36, and shifts to the state shown in the upper half of the page.

  At this time, the B2 relay valve 38 is in the state shown in the upper half of FIG. More specifically, the regulator pressure Pr is supplied to the right end of the B2 relay valve 38 by bringing the ON / OFF electromagnetic valve 30 into a communicating state. Thereby, the B2 relay valve 38 is brought into the state shown in the upper half of FIG.

  Thereby, the control pressure PL1 regulated and output by the SL1 solenoid valve 20 is supplied to the B2 brake 12 via the B1 relay valve 36 and the B2 relay valve 38. That is, the oil passage is switched by the manual valve 40 and the ON / OFF electromagnetic valve 30, and the engagement element to which the output pressure of the L1 solenoid valve 20 is supplied is changed from the B1 brake 11 to the B2 brake 12.

  As a result, the control pressure PL1 regulated and output by the SL1 solenoid valve 20 passes through the B1 relay valve 36 and the fail-safe valve 34, and is supplied to the B1 brake 11. Further, the control pressure PL2 regulated by the SL2 silenoid valve 22 is supplied to the C2 clutch 16 through the shift valve 42.

  As described above, the engagement elements that establish the engine brake range, that is, the B2 brake 12 and the C2 clutch 16 can be engaged with each other.

  As described above, the oil path is switched by the manual valve 40 and the ON / OFF electromagnetic valve 30 in the normal D range and in the engine brake range. Thereby, the engagement element to which the output pressure of the SL1 solenoid valve 20 is supplied is changed. Accordingly, the SL1 solenoid valve 20 can control the B1 brake 11 and the B2 brake 12 which are engaging elements.

  This makes it possible to perform shift control equivalent to the conventional one in the hydraulic control device 60 in which the number of used linear solenoid valves is reduced.

<Switching to fail-safe circuit>
Further, the present invention includes a lockup solenoid valve 26 that can output a surplus pressure higher than the normal region pressure, and a shift valve 42 that is a spool valve that is operated by the surplus pressure of the lockup solenoid valve 26.

  As shown in FIG. 6, in order to configure the third speed, it is necessary to engage the C2 clutch 16 and the C3 clutch 17 respectively. For example, during traveling at the fourth speed, that is, while traveling with the B1 brake 11 and the C3 clutch 17 engaged, for example, as shown in FIG. It is assumed that the SL2 solenoid valve 22 has failed.

  As shown in FIG. 8A, the SL2 silenoid valve 22 that is not used in the fourth speed is used in the normal third speed and engages the C2 clutch 16. However, when the SL2 solenoid valve 22 fails, the SL2 solenoid valve 22 may not output the pressure necessary for engaging the C2 clutch 16.

  If the vehicle stops at the 4th speed, the gear ratio is large, so that the rotational power input from the engine cannot be sufficiently decelerated and re-start is impossible. Therefore, in the above example, it is necessary to establish the third speed by engaging the C2 clutch 16 with some pressure.

  In the hydraulic control device 60 of the present invention, when the shift control solenoid valve or the electronic control means for controlling the stepped automatic transmission is in a failed state, an excessive pressure higher than the normal range pressure is applied from the lockup solenoid valve 26. When output, the shift valve 42 switches the oil path of the SL3 solenoid valve 24, which is a shift control solenoid valve, and a fail-safe circuit is configured to establish the third speed.

  The switching to the fail-safe circuit will be described in detail with reference to FIG. 3 which is a schematic diagram of the hydraulic circuit for explaining the configuration of the fail-safe circuit in the hydraulic control apparatus according to the embodiment of the present invention. The engagement elements that need to be engaged to establish the third speed are the C2 clutch 16 and the C3 clutch 17 as shown in FIG.

  When the shift control solenoid valve or the electronic control means for controlling the stepped automatic transmission is in a failed state, it is detected by a failure state detection means (not shown), and when the failure state is determined, the lockup solenoid valve 26 is detected. To the surplus pressure Pf higher than the normal pressure.

  The surplus pressure Pf is introduced to the right end of the shift valve 42 as shown in FIG. A spring 42a is disposed on the right side of the shift valve 42 in the drawing. The spring 42a normally maintains the shift valve 42 in the state shown in the upper half of FIG. 3, and the shift valve 42 is moved to the lower side of FIG. 3 only when the excess pressure Pf is introduced into the right end of the shift valve 42 in the drawing. The spring constant is set to shift to the state shown in half.

  When the shift valve 42 is shifted to the state shown in the lower half of FIG. 3, the regulator pressure Pr is introduced from the manual valve 40 to the shift valve 42. The regulator pressure Pr is supplied to the C2 clutch 16 via the shift valve 42 in the state shown in the lower half of FIG. Thereby, the C2 clutch 16 is engaged.

  When the shift valve 42 is shifted to the state shown in the lower half of FIG. 3, the exhaust pressure (EX pressure) Pex of the SL3 solenoid valve 24 is introduced from the exhaust port S3ex to the shift valve 42. This discharge pressure Pex is introduced into the intake port S3in of the SL3 solenoid valve 24 via the shift valve 42, and is introduced into the C3 clutch 17 from the discharge port S3out of the SL3 solenoid valve 24. Thereby, the C3 clutch 17 is engaged.

  As described above, even when the shift control solenoid valve or the electronic control means for controlling the stepped automatic transmission (not shown) is in a failed state (failed), the C2 clutch 16 is configured by configuring the fail safe circuit, The third gear is established by engaging the C3 clutch 17.

  Thereby, in the hydraulic control device 60 in which the number of linear solenoid valves to be used is reduced, the same limp home as in the past can be realized.

<Switching of the original pressure of the hydraulic pressure supplied to the engagement element during reverse movement>
Further, in the present invention, the original pressure of the hydraulic pressure supplied to the B2 brake 12 which is an engagement element used at the time of reverse movement is regulated by the SL1 solenoid valve 20 by the ON / OFF solenoid valve 30 which is a normally closed solenoid valve. The control pressure PL1 thus output is switched to the reverse line pressure Pb.

  FIG. 4 is a schematic diagram of a hydraulic circuit for explaining switching of control hydraulic pressure at the time of reverse in the hydraulic control device according to one embodiment of the present invention, and FIG. The switching of the original pressure of the supplied hydraulic pressure will be described in detail.

  As shown in FIG. 6, the B2 brake 12 and the C1 clutch 15 are engaged when reversing. When shifted to the reverse range, the electronic control means (not shown) of the hydraulic control device 60 brings the ON / OFF solenoid valve 30 into a communicating state. As a result, the supply destination of the control pressure PL1, which is regulated and output by the SL1 solenoid valve 20, is the same as described above in <Switching of oil path of control pressure output from the shift control solenoid valve> The B1 brake 11 is switched to the B2 brake 12.

  Further, at the time of reverse, the reverse line pressure Pb is introduced from the manual valve 40 to the C1 clutch 15.

  As described above, the control pressure is supplied to and engaged with the B2 brake 12 and the C1 clutch 15 that need to be engaged during reverse. Thereby, a power transmission path in the reverse range is configured. That is, the original pressure of the hydraulic pressure supplied to the B2 brake 12 at this time is the control pressure PL1 that has been regulated by the SL1 solenoid valve 20 and output.

  By the way, when traveling in the reverse range, the required pressure for maintaining the B2 brake 12 in the engaged state is higher than when traveling forward. The maximum value of the pressure for controlling the released B2 brake 12 to the engaged state is set while ensuring the controllability at the time of engagement of PL1, which is the control source pressure of the B2 brake 12.

  On the other hand, the necessary pressure for maintaining the B2 brake 12 in the engaged state requires a pressure corresponding to the engine torque of the vehicle (not shown) that is running, for example, climbing a steep hill backward. When the engine torque increases, the engaged state may not be maintained with PL1 that is the control source pressure of the B2 brake 12.

  As described above, when the engagement state of the B2 brake 12 cannot be maintained, the brake plate (not shown) constituting the B2 brake 12 and the brake disc are relatively rotated and damaged.

  Therefore, when traveling in the reverse range, it is necessary to supply the B2 brake 12 with the reverse line pressure Pb that is higher than the control pressure PL1 for performing the engagement control.

  As described above, the reverse line pressure Pb is supplied to the B2 brake 12 that has been engaged by the control pressure PL1 regulated by the SL1 solenoid valve 20.

  More specifically, the ON / OFF electromagnetic valve 30 is brought into the communication state, the engagement control of the B2 brake 12 is performed, and when the engagement control is completed, the ON / OFF electromagnetic valve 30 is shifted to the cutoff state.

  As described above, the regulator pressure Pr supplied from the ON / OFF electromagnetic valve 30 to the B2 relay valve 38 is not supplied. As a result, the B2 relay valve 38 shifts from the state shown in the upper half of FIG. 4 to the state shown in the lower half. Thereby, the control pressure PL1 supplied to the B2 brake 12 via the B2 relay valve 38 is blocked by the B2 relay valve 38.

  At this time, the reverse line pressure Pb introduced from the manual valve 40 to the C1 clutch 15 passes through the B2 relay valve 38 and is also introduced into the B2 brake 12. As a result, the pressure introduced into the B2 brake 12 is switched from the control pressure PL1 to the reverse line pressure Pb.

  Thus, the switching of the hydraulic pressure supplied to the engagement element used at the time of reverse is completed. Thus, even when a large engine torque is input to the stepped automatic transmission during reverse, it is possible to prevent the B2 brake 12 that is an engagement element during reverse from slipping and maintain the engaged state. Therefore, damage due to relative rotation between a brake plate (not shown) constituting the B2 brake 12 and the brake disk can be prevented.

As a result, in the hydraulic control device 60 in which the number of used linear solenoid valves is reduced, it is possible to travel in the same reverse direction as in the past.

  As described above, according to the hydraulic control device 60 of the present invention, the number of linear solenoid valves to be used is reduced, and the cost and the volume and weight of the hydraulic control device are reduced, and the fail-safe circuit. The limp home is possible, and low fuel consumption performance and shift performance can be maintained.

  The embodiment and concept of the hydraulic control device of the present invention have been described above, but the present invention is not limited to this, and the scope does not depart from the spirit and teaching described in the claims and the description. It will be understood by those skilled in the art that other variations and improvements can be obtained.

11 B1 Brake 12 B2 Brake 15 C1 Clutch 16 C2 Clutch 17 C3 Clutch 20 SL1 Solenoid Valve 22 SL2 Silenoid Valve 24 SL3 Silenoid Valve 26 Lockup Solenoid Valve 28 Line Pressure Control Solenoid Valve 30 ON / OFF Solenoid Valve 32 Maximum Pressure Selection Valve 33 Reverse control valve 34 Fail safe valve 34a Spring disposed on fail safe valve 36 B1 relay valve 36a Spring disposed on B2 relay valve 38 B2 relay valve 39 B2 pressure control valve 40 Manual valve 42 Shift valve 42a Shift valve Spring provided 44 Primary regulator valve 46 Secondary regulator valve 46a Spring provided in the secondary regulator valve 47 Lock-up switching valve 48 Lock-up control valve 50 Torque converter 55 Oil Generating means 60 Hydraulic control device 62 Hydraulic circuit used in hydraulic control device 70 Planetary gear mechanism 160 Conventional hydraulic control device 162 Hydraulic circuit used in conventional hydraulic control device Pp Oil pump pressure Pr Regulator pressure PL of conventional hydraulic control device Control source pressure PLx Control source pressure of the hydraulic control device of the present invention P1 Control pressure adjusted by the SL1 solenoid valve P2 Control pressure adjusted by the SL2 solenoid valve P3 Control pressure adjusted by the SL3 solenoid valve Pb Backward Line pressure Pt Direct connection control pressure Pf Excess pressure during failure

Claims (3)

A hydraulic control device for a stepped automatic transmission for a vehicle,
A plurality of shift control solenoid valves;
An output control pressure of the shift control solenoid valve is introduced, a maximum pressure selection valve that selects and outputs a maximum hydraulic pressure from the output control pressure; and
A manual valve that switches the oil path by a shift operation,
It has a normally closed solenoid valve,
A power transmission element constituting the planetary gear mechanism;
A plurality of engagement elements that lock or synchronize rotation of the power transmission element,
The control source pressure is regulated by the output pressure of the maximum pressure selection valve,
The oil passage is switched by the manual valve and the normally closed electromagnetic valve, and the engagement element to which the output pressure of the shift control solenoid valve is supplied is changed.
A hydraulic control device characterized by that. A solenoid valve capable of outputting a surplus pressure higher than the normal range pressure;
A spool valve that operates by surplus pressure of the solenoid valve,
When surplus pressure higher than the normal pressure is output from the solenoid valve,
With the spool valve,
The oil passage of the shift control solenoid valve is switched,
A predetermined gear position is established at the time of failure,
The hydraulic control device according to claim 1. With the normally closed solenoid valve, the hydraulic pressure supplied to the engagement element used at the time of reverse is switched from the output control pressure to the line pressure for reverse.
The hydraulic control device according to claim 1, wherein