Damping pressure supply circuit with wheel pressure control valve

Abstract

The present invention provides a damping pressure supply circuit for a pulley pressure control valve to ensure the controllability of a locking clutch and the damping property of the pulley pressure control valve. The hydraulic control circuit comprises: a pressure regulating valve, a first pilot valve, a second pilot valve, and a third pilot valve. The first pilot pressure is introduced as a source pressure into a primary solenoid valve for generating a primary signal pressure and a secondary solenoid valve for generating a secondary signal pressure. The second pilot pressure is introduced as a source pressure into a locking solenoid valve for generating a locking signal pressure. The third pilot pressure is introduced as a damping pressure into a primary regulating valve for controlling a primary pulley pressure based on a primary signal pressure and a secondary regulating valve for controlling a secondary pulley pressure based on a secondary signal pressure.

Description

Technical Field

[0001] The invention relates to a damping pressure supply circuit of a pulley pressure control valve. Background Art

[0002] In Patent Document 1 Figure 2 In the patent document 1, a hydraulic circuit diagram showing the general situation in the control valve unit of a continuously variable transmission has been disclosed. Figure 2 As shown, a pilot valve (25) is provided in an oil circuit (402) branched from an oil circuit (401), and the pilot valve (25) generates a predetermined pressure according to the line pressure and outputs it to the pilot pressure oil circuit (403). Thus, the original pressure of the signal pressure output from the line pressure solenoid valve (30), the clutch pressure solenoid valve (31), the lock solenoid valve (32), the primary solenoid valve (33), and the secondary solenoid valve (34) is generated.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2016 / 006356 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] As an improvement to the above hydraulic circuit, it is conceivable to add another pilot valve. By reducing the pressure in two stages using two pilot valves, two types of pilot pressure, low pressure and high pressure, can be generated.

[0008] In this case, it is possible to consider using two types of pilot pressures for each solenoid valve separately. Specifically, it is possible to consider using the high-pressure pilot pressure as the source pressure of the line pressure solenoid valve, the clutch pressure solenoid valve, the primary solenoid valve, and the secondary solenoid valve, and using the low-pressure pilot pressure as the source pressure of the lock solenoid valve. In addition, it is possible to consider using the low-pressure pilot pressure as a damping pressure and introducing it into the regulating valve that controls the primary pulley pressure and the secondary pulley pressure, that is, the pulley pressure control valve.

[0009] However, when the low pressure pilot pressure is above the lower limit of the setting range of the line pressure, when the line pressure is below the low pressure pilot pressure, both pilot valves output the line pressure as the pilot pressure. That is, in this case, the low pressure pilot pressure becomes the line pressure.

[0010] Therefore, in this case, the vibration of the line pressure, that is, the repetition of the up and down changes of the line pressure becomes the vibration of the damping pressure of the pulley control valve, and there is a possibility that the primary pulley pressure and the secondary pulley pressure will change.

[0011] In addition, when the pilot pressure as the source pressure of the lock-up solenoid valve decreases, the usable range of the signal pressure becomes narrower. Therefore, if the low pressure pilot pressure is set too low, the controllability of the lock-up clutch deteriorates and engagement shock may occur.

[0012] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to ensure the controllability of the lock-up clutch and the damping performance of the pulley pressure control valve.

[0013] Technical solutions for solving technical problems

[0014] A damping pressure supply circuit of a pulley pressure control valve according to a certain aspect of the present invention comprises: a pressure regulating valve for regulating the discharge oil of an oil pump to a line pressure, a first pilot valve for generating a first pilot pressure using the line pressure as a source pressure, a second pilot valve for generating a second pilot pressure using the first pilot pressure as a source pressure, and a third pilot valve for generating a third pilot pressure using the second pilot pressure as a source pressure. The first pilot pressure is introduced as a source pressure to a primary solenoid valve for generating a primary signal pressure, which is a signal pressure for controlling a primary pulley pressure of a belt-type continuously variable transmission, and a secondary solenoid valve for generating a secondary signal pressure, which is a signal pressure for controlling a secondary pulley pressure of the belt-type continuously variable transmission. The second pilot pressure is introduced as a source pressure to a lockup solenoid valve for generating a signal pressure for controlling a lockup pressure of a lockup clutch of a torque converter. The third pilot pressure is introduced as a damping pressure to a primary pulley pressure control valve for controlling the primary pulley pressure based on the primary signal pressure, and a secondary pulley pressure control valve for controlling the secondary pulley pressure based on the secondary signal pressure.

[0015] Effects of the Invention

[0016] According to the above aspect, the second pilot pressure having the source pressure function of the lock-up solenoid valve is used as the source pressure to generate the third pilot pressure, so that the third pilot pressure has the damping pressure function of the pulley pressure control valve. Therefore, the second pilot pressure can be set to an appropriate value, and the third pilot pressure can be set to be lower than the lower limit of the setting range of the line pressure. Therefore, the controllability of the lock-up clutch and the damping property of the pulley pressure control valve can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural overview diagram of the vehicle.

[0018] Figure 2 It is a structural overview diagram of the hydraulic control circuit. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0020] Figure 1: is a schematic diagram of the structure of a vehicle. The vehicle includes an engine ENG, a torque converter TC, a forward / reverse switching mechanism SWM, and a converter VA. In the vehicle, a transmission TM is a belt-type continuously variable transmission including a torque converter TC, a forward / reverse switching mechanism SWM, and a converter VA.

[0021] The engine ENG constitutes a driving source of the vehicle. The power of the engine ENG is transmitted to the drive wheels DW via the torque converter TC, the forward / reverse switching mechanism SWM, and the inverter VA. In other words, the torque converter TC, the forward / reverse switching mechanism SWM, and the inverter VA are provided on a power transmission path connecting the engine ENG and the drive wheels DW.

[0022] The torque converter TC transmits power via a fluid. In the torque converter TC, by engaging the lockup clutch LU, it is possible to improve power transmission efficiency.

[0023] The forward / reverse switching mechanism SWM is provided on the power transmission path connecting the engine ENG and the inverter VA. The forward / reverse switching mechanism SWM switches the forward / reverse direction of the vehicle by switching the rotation direction of the input rotation. The forward / reverse switching mechanism SWM has a forward clutch FWD / C that is engaged when the forward gear is selected, and a reverse brake REV / B that is engaged when the reverse gear is selected. When the forward clutch FWD / C and the reverse brake REV / B are released, the transmission TM is in a neutral state, that is, a power cut-off state.

[0024] The inverter VA constitutes a belt-type continuously variable transmission mechanism having a primary pulley PRI, a secondary pulley SEC, and a belt BLT wound around the primary pulley PRI and the secondary pulley SEC. A hydraulic pressure Ppri of the primary pulley PRI is supplied to the primary pulley PRI, and a secondary pulley pressure Psec of the secondary pulley SEC is supplied to the secondary pulley SEC from a hydraulic control circuit 1 described later.

[0025] The transmission TM is configured to further include a mechanical oil pump MP, an electric oil pump EP, and a motor M. The mechanical oil pump MP presses oil to the hydraulic control circuit 1. The mechanical oil pump MP is driven by the power of the engine ENG. The electric oil pump EP presses oil to the hydraulic control circuit 1 together with the mechanical oil pump MP or alone. The electric oil pump EP is provided to assist the mechanical oil pump MP. The motor M drives the electric oil pump EP. The electric oil pump EP can also be understood to be configured to include the motor M.

[0026] The transmission TM is further configured to include a hydraulic control circuit 1 and a transmission controller 2. The hydraulic control circuit 1 is configured of a plurality of flow paths and a plurality of hydraulic control valves, and regulates the pressure of oil supplied from the mechanical oil pump MP and the electric oil pump EP and supplies the oil to various parts of the transmission TM.

[0027] The transmission controller 2 is a controller for controlling the transmission TM, and controls the hydraulic control circuit 1 and the electric oil pump EP based on signals input from various sensors, etc. The hydraulic control circuit 1 hydraulically controls the lockup clutch LU, the forward clutch FWD / C, the reverse brake REV / B, the primary pulley PRI, and the secondary pulley SEC, etc. based on instructions from the transmission controller 2.

[0028] Figure 2 1 is a schematic diagram of the structure of the hydraulic control circuit 1. The hydraulic control circuit 1 includes a pressure regulating valve 11, a primary regulating valve 12, a secondary regulating valve 13, a clutch regulating valve 14, a torque converter regulating valve 15, a lockup regulating valve 16, a first pilot valve 17, a line pressure solenoid valve 18, a primary solenoid valve 19, a secondary solenoid valve 20, a clutch pressure solenoid valve 21, a second pilot valve 22, a lockup solenoid valve 23, and a third pilot valve 24.

[0029] The pressure regulating valve 11 regulates the pressure of the discharged oil of at least one of the mechanical oil pump MP and the electric oil pump EP to the line pressure PL. The dotted line pointing to the line pressure PL indicates that it points to the hydraulic pressure rather than the oil line. The pressure regulating valve 11 discharges a part of the discharged oil of the oil pump and regulates the pressure. The oil regulated to the line pressure PL is supplied to the primary regulating valve 12, the secondary regulating valve 13, and the first pilot valve 17.

[0030] The primary regulator valve 12 and the secondary regulator valve 13 are pulley pressure control valves, which control the pulley pressure by regulating the oil regulated to the line pressure PL to the pulley pressure. The pulley pressure is the primary pulley pressure Ppri in the case of the primary regulator valve 12 and the secondary pulley pressure Psec in the case of the secondary regulator valve 13.

[0031] The clutch regulating valve 14 is supplied with the oil discharged from the pressure regulating valve 11. The clutch regulating valve 14 regulates the pressure of the oil discharged from the pressure regulating valve 11 to the clutch pressure. The oil regulated to the clutch pressure is selectively supplied to either the forward clutch FWD / C or the reverse brake REV / B. The clutch regulating valve 14 discharges a part of the oil and regulates the pressure.

[0032] The oil discharged from the clutch regulating valve 14 is supplied to the torque converter regulating valve 15. The torque converter regulating valve 15 regulates the pressure of the oil discharged from the pressure regulating valve 11 to the torque converter pressure of the torque converter TC. The torque converter regulating valve 15 discharges a part of the oil, regulates the pressure, and supplies the discharged oil to the lubrication system of the transmission TM. The oil regulated to the torque converter pressure is supplied to the torque converter TC and the lockup regulating valve 16.

[0033] The lock-up regulating valve 16 regulates the oil pressure regulated to the torque converter pressure to the lock-up pressure. The lock-up clutch LU performs lock-up control using the lock-up differential pressure which is the differential pressure between the torque converter pressure and the lock-up pressure. The oil pressure regulated to the lock-up pressure is supplied to the lock-up clutch LU.

[0034] The pressure regulating valve 11 regulates the pressure based on the signal pressure generated by the line pressure solenoid valve 18. The same is true for the primary regulating valve 12 and primary solenoid valve 19, the secondary regulating valve 13 and secondary solenoid valve 20, the clutch regulating valve 14 and clutch pressure solenoid valve 21, and the lockup regulating valve 16 and lockup solenoid valve 23.

[0035] The first pilot pressure P1 is introduced as a source pressure to the line pressure solenoid valve 18, the primary solenoid valve 19, the secondary solenoid valve 20, and the clutch pressure solenoid valve 21. The first pilot pressure P1 is generated by the first pilot valve 17 using the line pressure PL as a source pressure. The first pilot pressure P1 is also introduced to the second pilot valve 22.

[0036] The second pilot valve 22 generates a second pilot pressure P2 using the first pilot pressure P1 as a source pressure. The second pilot pressure P2 is set to be equal to or higher than the lower limit of the setting range of the line pressure PL. The second pilot pressure P2 is set in advance in consideration of the controllability of the lockup clutch LU. The second pilot pressure P2 is introduced into the lockup solenoid valve 23 and the third pilot valve 24.

[0037] The lock-up solenoid valve 23 generates a lock-up signal pressure using the second pilot pressure P2 as a source pressure. The lock-up signal pressure is a signal pressure generated by the lock-up solenoid valve 23 to control the lock-up clutch LU of the torque converter TC.

[0038] The third pilot valve 24 generates a third pilot pressure P3 using the second pilot pressure P2 as the source pressure. The third pilot pressure P3 is set lower than the lower limit of the setting range of the line pressure PL. The third pilot pressure P3 is set in advance in consideration of the damping properties of the primary control valve 12 and the secondary control valve 13. The third pilot pressure P3 is introduced into the primary control valve 12 and the secondary control valve 13 as a damping pressure.

[0039] The third pilot pressure P3 introduced as the damping pressure is introduced into the primary regulating valve 12 in a direction opposite to the primary signal pressure. The primary signal pressure is a signal pressure generated by the primary solenoid valve 19 in order to control the primary pulley pressure Ppri.

[0040] Similarly, the third pilot pressure P3 introduced as the damping pressure is introduced into the secondary regulator valve 13 in opposition to the secondary signal pressure. The secondary signal pressure is a signal pressure generated by the secondary solenoid valve 20 in order to control the secondary pulley pressure Psec.

[0041] Next, the main effects of this embodiment will be described.

[0042] Here, assuming that the second pilot pressure P2 is introduced as the damping pressure into the primary control valve 12 and the secondary control valve 13 , the second pilot pressure P2 can have the source pressure function of the lockup solenoid valve 23 and the damping pressure function of the primary control valve 12 and the secondary control valve 13 , and the third pilot valve 24 is not required.

[0043] However, in this case, when the second pilot pressure P2 is high, it is necessary to strengthen the spring that urges the valve core against the force based on the damping pressure in each of the primary control valve 12 and the secondary control valve 13. However, in the hydraulic control circuit 1, the layout is strictly restricted, and it is difficult to establish the above spring. Therefore, in this case, it is necessary to reduce the second pilot pressure P2.

[0044] On the other hand, when the second pilot pressure P2 as the source pressure of the lock-up solenoid valve 23 is low, the use range of the lock-up signal pressure becomes narrower. Therefore, if the second pilot pressure P2 is set too low, the controllability of the lock-up clutch LU deteriorates, and there is a concern that engagement shock may occur.

[0045] Accordingly, when attempting to reduce the second pilot pressure P2 within a range in which the controllability of the lock-up clutch LU does not deteriorate, the second pilot pressure P2 may be set to be equal to or higher than the lower limit of the setting range of the line pressure PL.

[0046] The line pressure PL can be adjusted to the lower limit of the setting range during high-speed running. When the line pressure PL is lower than the second pilot pressure P2 during high-speed running, the line pressure PL is output from the second pilot valve 22 as the second pilot pressure P2.

[0047] At this time, the lockup clutch LU is still engaged. Therefore, even if the line pressure PL that is less than the second pilot pressure P2 is introduced into the lockup solenoid valve 23 as the second pilot pressure P2, the controllability of the lockup clutch LU is not affected.

[0048] However, when the line pressure PL as the second pilot pressure P2 is introduced as the damping pressure to the primary solenoid valve 19 and the secondary solenoid valve 20, the vibration of the line pressure PL becomes the vibration of the damping pressure. As a result, in this case, the primary pulley pressure Ppri and the secondary pulley pressure Psec may vary.

[0049] (1) The hydraulic control circuit 1 of the present embodiment corresponds to a damping pressure supply circuit of a pulley pressure control valve, and includes a pressure regulating valve 11, a first pilot valve 17, a second pilot valve 22, and a third pilot valve 24. The first pilot pressure P1 generated by the first pilot valve 17 is introduced as a source pressure to a primary solenoid valve 19 that generates a primary signal pressure and a secondary solenoid valve 20 that generates a secondary signal pressure. The second pilot pressure P2 generated by the second pilot valve 22 is introduced as a source pressure to a lock solenoid valve 23 that generates a lock signal pressure. The third pilot pressure P3 generated by the third pilot valve 24 is introduced as a damping pressure to a primary regulating valve 12 that controls a primary pulley pressure Ppri based on the primary signal pressure and a secondary regulating valve 13 that controls a secondary pulley pressure Psec based on the secondary signal pressure.

[0050] According to such a configuration, the third pilot pressure P3 is generated using the second pilot pressure P2 having the source pressure function of the lock-up solenoid valve 23 as the source pressure, and the third pilot pressure P3 has the damping pressure function of the primary regulator valve 12 and the secondary regulator valve 13 .

[0051] Therefore, according to such a configuration, the second pilot pressure P2 can be set to an appropriate level and the third pilot pressure P3 can be set to be lower than the lower limit of the setting range of the line pressure PL. Therefore, the controllability of the lockup clutch LU and the damping properties of the primary and secondary regulator valves 12 and 13 can be ensured.

[0052] (2) In the hydraulic control circuit 1 , the third pilot pressure P3 is introduced into the primary regulator valve 12 in opposition to the primary signal pressure, and is introduced into the secondary regulator valve 13 in opposition to the secondary signal pressure.

[0053] According to such a configuration, the third pilot pressure P3 can be caused to appropriately function as the damping pressure.

[0054] (3) In the hydraulic control circuit 1 , the second pilot pressure P2 is set to be equal to or higher than the lower limit of the setting range of the line pressure PL, and the third pilot pressure P3 is set to be lower than the lower limit of the setting range of the line pressure PL.

[0055] According to such a structure, the primary pulley pressure Ppri and the secondary pulley pressure Psec can be changed when the second pilot pressure P2 is introduced as the damping pressure of the primary regulating valve 12 and the secondary regulating valve 13, so that the controllability of the lockup clutch LU and the damping properties of the primary regulating valve 12 and the secondary regulating valve 13 can be properly ensured.

[0056] Although the embodiments of the present invention have been described above, the above embodiments merely represent a part of application examples of the present invention and are not intended to limit the technical scope of the present invention to the specific structures of the above embodiments.

[0057] Description of Reference Numerals

[0058] 1 hydraulic control circuit (damping pressure supply circuit); 11 pressure regulating valve; 12 primary regulating valve (primary pulley pressure control valve); 13 secondary regulating valve (secondary pulley pressure control valve); 17 first pilot valve; 19 primary solenoid valve; 20 secondary solenoid valve; 23 locking solenoid valve; 22 second pilot valve; 24 third pilot valve; EP mechanical oil pump (oil pump); LU locking clutch; MP electric oil pump (oil pump); TC torque converter; TM transmission (belt-type continuously variable transmission).

Claims

1. A damping pressure supply circuit with a pulley pressure control valve, characterized in that: have: A pressure regulating valve, which adjusts the discharge oil of the oil pump to the pipeline pressure; a first pilot valve, which uses the pipeline pressure as the original pressure to generate a first pilot pressure; a second pilot valve, which uses the first pilot pressure as a source pressure to generate a second pilot pressure; a third pilot valve, which uses the second pilot pressure as a source pressure to generate a third pilot pressure; The first pilot pressure is introduced as a source pressure into a primary solenoid valve and a secondary solenoid valve, wherein the primary solenoid valve generates a signal pressure, namely a primary signal pressure, for controlling a primary pulley pressure of a belt-type continuously variable transmission, and the secondary solenoid valve generates a signal pressure, namely a secondary signal pressure, for controlling a secondary pulley pressure of the belt-type continuously variable transmission. The second pilot pressure is introduced as a source pressure into a lock-up solenoid valve, and the lock-up solenoid valve generates a signal pressure for controlling a lock-up pressure of a lock-up clutch of a torque converter. The third pilot pressure is introduced as a damping pressure into a primary pulley pressure control valve that controls the primary pulley pressure based on the primary signal pressure and a secondary pulley pressure control valve that controls the secondary pulley pressure based on the secondary signal pressure.

2. The damping pressure supply circuit of the pulley pressure control valve according to claim 1, characterized in that: The third pilot pressure is introduced into the primary pulley pressure control valve in an opposite direction to the primary signal pressure, and is introduced into the secondary pulley pressure control valve in an opposite direction to the secondary signal pressure.

3. The damping pressure supply circuit of the pulley pressure control valve according to claim 1 or 2, characterized in that: The second pilot pressure is set to be above the lower limit of the setting range of the line pressure. The third pilot pressure is set to be lower than a lower limit of the setting range of the line pressure.

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