A control system, control device, and control method for a continuously variable transmission

Abstract

The application discloses a control device of a continuously variable transmission, which comprises a transmission body, a first clutch, a second clutch, a third clutch, a shift fork and a control system. The transmission body comprises an input shaft, an output shaft, a gear transmission assembly and a steel belt transmission assembly. The first clutch is engaged, the shift fork is in a first engagement position, the input shaft and the output shaft are driven by a first gear, the second clutch is engaged, the input shaft and the output shaft are driven by the steel belt transmission, the third clutch is engaged, the shift fork is in the first engagement position, and the input shaft reversely drives the output shaft by the first gear. The control system comprises four electromagnetic valves, the output ends of the electromagnetic valves are communicated with the first clutch, the second clutch, the shift fork and the third clutch respectively, and a controller is used for adjusting the output end pressure of the four electromagnetic valves. The application improves the slow starting response of the traditional continuously variable transmission and the poor transmission efficiency of the steel belt in the low speed ratio interval.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transmission control systems, in particular to a control system, a control device and a control method of a continuously variable transmission. BACKGROUND

[0002] As a core component in the transmission system, the main function of the transmission is to realize efficient power transmission and sensitive shift response.

[0003] The traditional continuously variable transmission uses steel belt transmission, which has the problems of low transmission efficiency and poor starting response in the low speed ratio range. The gear direct drive type continuously variable transmission uses gear transmission and steel belt transmission, which covers the working condition with low steel belt transmission efficiency, improves the transmission efficiency and improves the starting response.

[0004] There is an urgent need in the art for a control system to support the gear direct drive type continuously variable transmission to switch between two transmission modes. SUMMARY

[0005] The purpose of the present application is to provide a control device of a continuously variable transmission, which supports the gear direct drive type continuously variable transmission to switch between two transmission modes, and improves the problems of poor starting response and low transmission efficiency in the low speed ratio range of the traditional continuously variable transmission. Another purpose of the present application is to provide a control system of a continuously variable transmission, which supports the gear direct drive type continuously variable transmission to switch between two transmission modes, and improves the problems of poor starting response and low transmission efficiency in the low speed ratio range of the traditional continuously variable transmission. Another purpose of the present application is a control method of a continuously variable transmission, which supports the gear direct drive type continuously variable transmission to switch between two transmission modes, and improves the problems of poor starting response and low transmission efficiency in the low speed ratio range of the traditional continuously variable transmission.

[0006] To solve the above technical problems, the present application provides a control device of a continuously variable transmission, comprising:

[0007] The transmission body comprises an input shaft, an output shaft, a first gear transmission assembly and a steel belt transmission assembly, and further comprises a first clutch, a second clutch, a third clutch and a shift fork. The first clutch is in the engaged position. When the shift fork is in the first engaged position, the input shaft and the output shaft are driven through the first gear transmission assembly. When the second clutch is in the engaged position, the input shaft and the output shaft are driven through the steel belt transmission assembly. When the third clutch is in the engaged position, the input shaft drives the output shaft in reverse through the first gear transmission assembly.

[0008] The control system comprises a first electromagnetic valve, a second electromagnetic valve, a third electromagnetic valve and a fourth electromagnetic valve, an output end of the first electromagnetic valve is communicated with the first clutch, an output end of the second electromagnetic valve is communicated with the second clutch, an output end of the third electromagnetic valve is communicated with the shift fork, and an output end of the fourth electromagnetic valve is communicated with the third clutch.

[0009] A controller is used to adjust the output end pressure of the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve and the fourth electromagnetic valve according to the vehicle running state.

[0010] Based on the above arrangement, when the vehicle running speed is lower than the first preset vehicle speed, the output end pressure of the first electromagnetic valve and the third electromagnetic valve can be adjusted by the controller to make the first clutch be in the engaged position and the shift fork be in the first engaged position, and the output end pressure of the second electromagnetic valve and the fourth electromagnetic valve is adjusted to make the second clutch and the third clutch be in the separated position, at this time, the input shaft and the output shaft of the transmission are driven through the first gear, the transmission efficiency is improved, and the starting response is improved.

[0011] When the vehicle running speed is higher than the first preset vehicle speed, the output end pressure of the second electromagnetic valve can be adjusted by the controller to make the second clutch be in the engaged position, and the output end pressure of the first electromagnetic valve, the third electromagnetic valve and the fourth electromagnetic valve is adjusted to make the first clutch, the third clutch and the shift fork be in the separated position, at this time, the input shaft and the output shaft of the transmission are driven through the steel belt, and the vehicle speed change is more stable.

[0012] When reversing, the output end pressure of the third electromagnetic valve and the fourth electromagnetic valve is adjusted by the controller to make the third clutch be in the engaged position and the shift fork be in the first engaged position, and the output end pressure of the first electromagnetic valve and the second electromagnetic valve is adjusted to make the first clutch and the second clutch be in the separated position, at this time, the input shaft of the transmission is reversely driven through the first gear.

[0013] Therefore, the control device of the continuously variable transmission supports the gear direct drive type infinitely variable transmission to switch between two transmission modes, the gear transmission is used when starting or low-speed driving, the steel belt transmission is used when high-speed driving, and the transmission efficiency and starting response are improved.

[0014] Optionally, a second gear transmission assembly is further included, when the first clutch is in the engaged position and the shift fork is in the second engaged position, the input shaft and the output shaft are driven through the second gear transmission assembly, and the control system further comprises a fifth electromagnetic valve for switching the engaged position of the shift fork.

[0015] The application further provides a control system of a continuously variable transmission, comprising:

[0016] A first electromagnetic valve, an output end of which is communicated with the first clutch;

[0017] A second electromagnetic valve, an output end of which is communicated with the second clutch;

[0018] A third electromagnetic valve, an output end of which is communicated with the shift fork,

[0019] A fourth electromagnetic valve, an output end of which is communicated with the third clutch;

[0020] A controller, configured to adjust output end pressure of the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve and the fourth electromagnetic valve according to vehicle operating state.

[0021] The control system of the continuously variable transmission is applicable to the control device of the continuously variable transmission, and has the same technical effects as the control device of the continuously variable transmission, which will not be described herein.

[0022] Optionally, the output end of the third electromagnetic valve is also communicated with the fourth electromagnetic valve, and the control system further comprises a fifth electromagnetic valve, a first oil port of the fifth electromagnetic valve is connected with the output end of the third electromagnetic valve, a second oil port is communicated with an oil tank, a third oil port is communicated with one side cavity of the shift fork, a fourth oil port is communicated with the other side cavity of the shift fork, a first control end is an electromagnetic control end, and a second control end is a spring end.

[0023] When the fifth electromagnetic valve is located at a first working position, the first oil port and the third oil port of the fifth electromagnetic valve are in conduction, and the second oil port and the fourth oil port are in conduction; when the fifth electromagnetic valve is located at a second working position, the first oil port and the fourth oil port of the fifth electromagnetic valve are in conduction, and the second oil port and the third oil port are in conduction.

[0024] Optionally, the control system further comprises a sixth electromagnetic valve, the output end of the third electromagnetic valve is also communicated with the sixth electromagnetic valve, and an output end of the sixth electromagnetic valve is communicated with a parking oil cylinder.

[0025] The controller is further configured to adjust output end pressure of the sixth electromagnetic valve.

[0026] Optionally, the control system further comprises a switching valve, a first oil port of the switching valve is communicated with the output end of the second electromagnetic valve, a second oil port is communicated with the oil tank, a third oil port is communicated with the second clutch, a first control end is a spring end, and a second control end is communicated with the output end of the sixth electromagnetic valve.

[0027] When the switching valve is located at a first working position, the first oil port and the third oil port are in conduction; when the switching valve is located at a second working position, the second oil port and the third oil port are in conduction.

[0028] Optionally, a mechanical pump is further included, an oil outlet of the mechanical pump being communicated with the main oil passage, a branch of the main oil passage including a first branch and a second branch, the first electromagnetic valve and the second electromagnetic valve being arranged in the first branch, and the third electromagnetic valve being arranged in the second branch;

[0029] A pressure reducing valve is further included for adjusting the oil pressure of the first branch to a preset pressure.

[0030] Optionally, a first oil port of the pressure reducing valve is communicated with the main oil passage, a second oil port is communicated with the oil tank, a third oil port is communicated with the first branch, a first control end is a spring end, and a second control end is communicated with the third oil port thereof;

[0031] The pressure reducing valve is in a first working position in which the first oil port is communicated with the third oil port, and in a second working position in which the second oil port is communicated with the third oil port.

[0032] Optionally, a third branch is further included in the branch of the main oil passage, the second branch being communicated with an oil inlet end of the driven oil cylinder, and the third branch being communicated with an oil inlet end of the driving oil cylinder, and further comprising:

[0033] A driving pressure regulating valve for adjusting the hydraulic oil pressure entering the driving oil cylinder;

[0034] A driven pressure regulating valve for adjusting the hydraulic oil pressure entering the driven oil cylinder.

[0035] Optionally, a seventh electromagnetic valve is further included, a first oil port of the seventh electromagnetic valve being communicated with the first branch, a second oil port being communicated with the oil tank, and a third oil port being communicated with a first control end of the driven pressure regulating valve, a second control end of the driven pressure regulating valve being a spring end and being further communicated with an oil passage between the driven pressure regulating valve and the driven oil cylinder;

[0036] The controller is further configured to adjust the output pressure of the third oil port of the seventh electromagnetic valve.

[0037] Optionally, an eighth electromagnetic valve is further included, a first oil port of the eighth electromagnetic valve being communicated with the first branch, a second oil port being communicated with the oil tank, and a third oil port being communicated with a first control end of the driving pressure regulating valve, a second control end of the driving pressure regulating valve being a spring end and being further communicated with an oil passage between the driving pressure regulating valve and the driving oil cylinder;

[0038] The controller is further configured to adjust the output pressure of the third oil port of the eighth electromagnetic valve.

[0039] Optionally, further comprising:

[0040] An electronic pump;

[0041] An electronic pump switching valve, an oil inlet of which is communicated with an oil outlet of the electronic pump, a first oil outlet is communicated with the pressure reducing valve, the driven pressure regulating valve and the third electromagnetic valve, a second oil outlet is communicated with the first cooling and lubricating branch, and a first control end is a spring end, a second control end is communicated with an output end of the second electromagnetic valve, when the electronic pump switching valve is in a first working position, the oil inlet is communicated with the first oil outlet; when the electronic pump switching valve is in a second working position, the oil inlet is communicated with the second oil outlet.

[0042] An electronic pump pressure regulating valve, which is used to regulate the oil inlet pressure of the electronic pump switching valve according to the output end pressure of the first electromagnetic valve and the fourth electromagnetic valve.

[0043] Optionally, two one-way valves are further included, so that the hydraulic oil can only flow from the first oil outlet of the electronic pump switching valve to the pressure reducing valve, the driven pressure regulating valve and the third electromagnetic valve in one direction.

[0044] Optionally, the mechanical pump includes a first oil outlet and a second oil outlet, both of which are connected with the main oil circuit, and a one-way valve is further arranged between the first oil outlet and the second oil outlet, so that the hydraulic oil from the second oil outlet can only flow to the main oil circuit in one direction, and the hydraulic pump further includes:

[0045] An oil pump switching valve, a first oil port of which is communicated with the first oil outlet of the mechanical pump, a second oil port of which is communicated with an oil tank, and when the oil pump switching valve is in a first working position, the first oil port and the second oil port are communicated; when the oil pump switching valve is in a second working position, the first oil port and the second oil port are isolated.

[0046] Optionally, the hydraulic system further includes:

[0047] A ninth electromagnetic valve, a first oil port of which is communicated with a third oil port of the pressure reducing valve, a second oil port of which is communicated with the oil tank, the third oil port is communicated with the first control end of the oil pump switching valve, and a first control end of the ninth electromagnetic valve is an electromagnetic control end, and a second control end is a spring end;

[0048] When the ninth electromagnetic valve is in a first working position, the second oil port and the third oil port are communicated; when the ninth electromagnetic valve is in a second working position, the first oil port and the third oil port are communicated.

[0049] The second control end of the oil pump switching valve is a spring end

[0050] Optionally, the hydraulic system further includes:

[0051] A main oil circuit pressure regulating valve, an oil inlet of which is communicated with the main oil circuit, a first oil outlet of which is communicated with the secondary oil circuit, and a second oil outlet of which is communicated with the oil tank, when the main oil circuit pressure regulating valve is in a first working position, the oil inlet is communicated with the first oil outlet and the second oil outlet; when the main oil circuit pressure regulating valve is in a second working position, the oil inlet is communicated with the first oil outlet; when the main oil circuit pressure regulating valve is in a third working position, the oil inlet, the first oil outlet and the second oil outlet are all isolated.

[0052] a tenth solenoid valve, an output end of which is communicated with a spring end of the main oil way pressure regulating valve, and an opposite control end of which is communicated with an oil inlet of the main oil way pressure regulating valve;

[0053] The controller is further configured to adjust the pressure of the output end of the tenth solenoid valve.

[0054] Optionally, further comprising:

[0055] a main oil way safety valve, an oil inlet of which is communicated with the main oil way, an oil outlet of which is communicated with an oil tank, a first control end of which is communicated with the main oil way, and a second control end of which is a spring end and is further communicated with a third oil port of the pressure reducing valve, and under normal circumstances, the oil inlet of the main oil way safety valve is cut off from the oil outlet.

[0056] Optionally, further comprising:

[0057] a torque converter reversing valve, a first oil port of which is communicated with a first oil outlet of the main oil way pressure regulating valve through the secondary oil way, a second oil port of which is communicated with the oil tank, a third oil port of which is communicated with a locking cavity of the torque converter, a fourth oil port of which is communicated with a second cooling and lubricating branch, and a fifth oil port of which is communicated with an unlocking cavity of the torque converter;

[0058] a torque converter pressure regulating valve, a first oil port of which is communicated with the first branch, a second oil port of which is communicated with a sixth oil port of the torque converter reversing valve, and a third oil port of which is communicated with the oil tank, and when the torque converter pressure regulating valve is in a first working position, the second oil port and the third oil port of the torque converter pressure regulating valve are communicated; when the torque converter pressure regulating valve is in a second working position, the first oil port and the second oil port of the torque converter pressure regulating valve are communicated.

[0059] when the torque converter reversing valve is in an unlocking position state, the third oil port and the fourth oil port of the torque converter reversing valve are communicated, and the first oil port and the fifth oil port of the torque converter reversing valve are communicated; when the torque converter reversing valve is in a locking position state, the sixth oil port of the torque converter reversing valve is communicated with the third oil port, the first oil port of the torque converter reversing valve is communicated with the fourth oil port, and the fifth oil port of the torque converter reversing valve is communicated with the second oil port.

[0060] Optionally, further comprising:

[0061] an eleventh solenoid valve, a first oil port of which is communicated with the first branch, a second oil port of which is communicated with the oil tank, and a third oil port of which is communicated with a first control end of the torque converter reversing valve and a first control end of the torque converter pressure regulating valve respectively;

[0062] a second control end of the torque converter reversing valve is a spring end;

[0063] a second control end of the torque converter pressure regulating valve is a spring end and is further communicated with the second oil port of the torque converter pressure regulating valve;

[0064] The controller is further configured to adjust the output pressure of the third oil port of the eleventh electromagnetic valve.

[0065] Optionally, an oil cooler, a filter press and a nozzle are sequentially connected, and the first cooling lubrication branch and the second cooling lubrication branch are respectively provided with a check valve to allow hydraulic oil to be unidirectionally collected in the oil cooler.

[0066] Optionally, a safety valve is further included and arranged between the electronic pump and the electronic pump switching valve.

[0067] The application further provides a control method of the gear direct drive continuously variable transmission.

[0068] When the vehicle is in the forward state and the vehicle speed is lower than a first preset rotating speed, the first clutch is controlled to be in the engaged position, the shift fork is controlled to be in the first engaged position, and the input shaft and the output shaft of the gear direct drive continuously variable transmission are driven by the first gear transmission assembly.

[0069] When the vehicle is in the forward state and the vehicle speed is higher than the first preset rotating speed, the second clutch is controlled to be in the engaged position, and the input shaft and the output shaft are driven by the steel belt transmission assembly.

[0070] When the vehicle is in the reverse state, the third clutch is controlled to be in the engaged position, the shift fork is controlled to be in the first engaged position, and the input shaft reversely drives the output shaft by the first gear transmission assembly.

[0071] The control method of the gear direct drive continuously variable transmission is suitable for the control device of the continuously variable transmission, and has the same technical effects as the control device of the continuously variable transmission, which will not be described herein.

[0072] The application further provides a control method of the gear direct drive continuously variable transmission.

[0073] When the vehicle is in the forward state and the vehicle speed is lower than a first preset rotating speed, the first clutch is controlled to be in the engaged position, the shift fork is controlled to be in the first engaged position, and the input shaft and the output shaft of the gear direct drive continuously variable transmission are driven by the first gear transmission assembly.

[0074] When the vehicle is in the forward state and the vehicle speed is higher than the first preset rotating speed, the second clutch is controlled to be in the engaged position, and the input shaft and the output shaft are driven by the steel belt transmission assembly.

[0075] When the vehicle is in the forward state and the vehicle speed is higher than the second preset rotating speed, the first clutch is controlled to be in the engaged position, the shift fork is controlled to be in the second engaged position, and the input shaft and the output shaft are driven by the second gear transmission assembly.

[0076] When reversing, the third clutch is controlled to be in the engaged position, the shift fork is in the first engaged position, and the input shaft drives the output shaft in reverse through the first gear transmission assembly.

[0077] The control method of the gear direct drive continuously variable transmission is applicable to the control device of the continuously variable transmission, and has the same technical effects as the control device of the continuously variable transmission, which will not be described herein. BRIEF DESCRIPTION OF DRAWINGS

[0078] Figure 1 The figure is a structural schematic diagram of a first specific embodiment of the gear direct drive continuously variable transmission.

[0079] Figure 2 The figure is a structural schematic diagram of a second specific embodiment of the gear direct drive continuously variable transmission. Figure 1 The figure is a transmission path diagram of the gear direct drive continuously variable transmission when the gear is driven.

[0080] Figure 3 The figure is a transmission path diagram of the gear direct drive continuously variable transmission when the gear is driven. Figure 1 The figure is a transmission path diagram of the gear direct drive continuously variable transmission when the gear is driven.

[0081] Figure 4 The figure is a structural schematic diagram of a second specific embodiment of the gear direct drive continuously variable transmission.

[0082] Figure 5 The figure is a transmission path diagram of the gear direct drive continuously variable transmission when the gear is driven. Figure 4 The figure is a transmission path diagram of the gear direct drive continuously variable transmission when the gear is driven.

[0083] Figure 6 The figure is a transmission path diagram of the gear direct drive continuously variable transmission when the gear is driven. Figure 4 The figure is a transmission path diagram of the gear direct drive continuously variable transmission when the gear is driven.

[0084] Figure 7 The figure is a structural schematic diagram of the gear direct drive continuously variable transmission when the steel belt is driven. Figure 4

[0085] The figure is a structural schematic diagram of a specific embodiment of the control system of the continuously variable transmission. Figure 8 The figure is a structural schematic diagram of a specific embodiment of the control system of the continuously variable transmission.

[0086] The figure is a structural schematic diagram of a specific embodiment of the control system of the continuously variable transmission. Figures 1 to 8 The figure is a structural schematic diagram of a specific embodiment of the control system of the continuously variable transmission.

[0087] 1-first solenoid valve; 2-second solenoid valve; 3-third solenoid valve; 4-fourth solenoid valve; 5-fifth solenoid valve; 6-sixth solenoid valve; 7-switching valve; 8-mechanical pump; 9-pressure reducing valve; 10-main oil line safety valve; 11-main drive pressure regulating valve; 12-following drive pressure regulating valve; 13-seventh solenoid valve; 14-eighth solenoid valve; 15-electronic pump; 16-electronic pump switching valve; 17-electronic pump pressure regulating valve; 18-check valve; 19-oil pump switching valve; 20-ninth solenoid valve; 21-main oil line pressure regulating valve; 22-tenth solenoid valve; 23-torque converter reversing valve; 24-torque converter pressure regulating valve; 25-eleventh solenoid valve; 26-oil cooler; 27-filter; 28-nozzle; 29-safety valve;

[0088] 01-first clutch; 02-second clutch; 03-third clutch; 04-shifting fork; 05-parking oil cylinder; 06-following oil cylinder; 07-driving oil cylinder; 08-hydraulic torque converter; 081-locking cavity; 082-unlocking cavity; I-input shaft; O-output shaft;

[0089] A-main oil line; A1-first branch; A2-second branch; A3-third branch; B-secondary oil line; C1-first cooling and lubricating branch; C2-second cooling and lubricating branch. DETAILED DESCRIPTION

[0090] In order to make the skilled in the art better understand the technical solutions of the present application, the present application will be further described in detail below in combination with the drawings and specific embodiments.

[0091] The words "first", "second", and the like described herein are only for the convenience of describing structures and / or functions of two or more structures or components that are the same or similar, and do not represent any special limitation on order and / or importance.

[0092] Please refer to Figures 1 to 3 , Figure 1 is a structural schematic diagram of the first specific embodiment of the gear direct drive continuously variable transmission; Figure 2 is Figure 1 the transmission path of the gear direct drive continuously variable transmission when the gear is driven; Figure 3 is Figure 1 the transmission path of the gear direct drive continuously variable transmission when the steel belt is driven.

[0093] The gear direct drive continuously variable transmission of the first embodiment not only has the structure of steel belt drive in the traditional continuously variable transmission, but also has a gear drive assembly. When the vehicle speed is lower than the first preset vehicle speed, the transmission is driven by the first gear; when the vehicle speed is higher than the first preset vehicle speed, the transmission is driven by the steel belt, which effectively improves the transmission efficiency and starting response.

[0094] Please refer to Figures 4 to 7, Figure 4 Structure diagram of the second embodiment of the gear direct drive continuously variable transmission; Figure 5 Figure 4 Transmission path diagram of the gear direct drive continuously variable transmission when the first gear is driven; Figure 6 Figure 4 Transmission path diagram of the gear direct drive continuously variable transmission when the second gear is driven; Figure 7 Figure 4 Structure diagram of the gear direct drive continuously variable transmission when the steel belt is driven

[0095] The second embodiment of the gear direct drive continuously variable transmission adds a two-gear transmission assembly. When the vehicle speed is lower than the first preset vehicle speed, i.e. in the low-speed ratio interval where the steel belt transmission efficiency is low, the transmission is driven by the first gear. When the vehicle speed is higher than the second preset vehicle speed, i.e. in the high-speed ratio interval where the steel belt transmission efficiency is low, the transmission is driven by the second gear. Only when the vehicle speed is between the first preset vehicle speed and the second preset vehicle speed, the transmission is driven by the steel belt. This improves the transmission efficiency and starting response while reducing the oil consumption of the hydraulic system.

[0096] The present application provides a control device, control system and control method for the above-mentioned gear direct drive continuously variable transmission, which will be described in detail below.

[0097] The present application provides a control device for a continuously variable transmission, comprising:

[0098] The transmission body comprises an input shaft I, an output shaft O, a first gear transmission assembly and a steel belt transmission assembly, and further comprises a first clutch 01, a second clutch 02, a third clutch 03 and a shift fork 04. When the first clutch 01 is in the engaged position and the shift fork 04 is in the first engaged position, the input shaft I and the output shaft O are driven by the first gear transmission assembly. When the second clutch 02 is in the engaged position, the input shaft I and the output shaft O are driven by the steel belt transmission assembly. When the third clutch 03 is in the engaged position and the shift fork 04 is in the first engaged position, the input shaft I is driven in reverse by the gear transmission assembly to drive the output shaft O.

[0099] The control system comprises a first electromagnetic valve 1, a second electromagnetic valve 2, a third electromagnetic valve 3 and a fourth electromagnetic valve 4. The output end of the first electromagnetic valve 1 is in communication with the first clutch 01. The output end of the second electromagnetic valve 2 is in communication with the second clutch 02. The output end of the third electromagnetic valve 3 is in communication with the shift fork 04. The output end of the fourth electromagnetic valve 4 is in communication with the third clutch 03.

[0100] The controller is used to adjust the output pressure of the first electromagnetic valve 1, the second electromagnetic valve 2, the third electromagnetic valve 3 and the fourth electromagnetic valve 4 according to the vehicle operating state.

[0101] ​​​Based on the above arrangement, when the vehicle speed is lower than the first preset vehicle speed, the output pressure of the first electromagnetic valve 1 and the third electromagnetic valve 3 can be adjusted by the controller to make the first clutch 01 in the engaged position, the fork 04 in the first engaged position, and the output pressure of the second electromagnetic valve 02 and the fourth electromagnetic valve 4 is adjusted to make the second clutch 02 and the third clutch 03 in the disengaged position, at this time, the input shaft I and the output shaft O of the transmission are driven through the first gear, which improves the transmission efficiency and improves the starting response.

[0102] When the vehicle speed is higher than the first preset vehicle speed, the output pressure of the second electromagnetic valve 2 can be adjusted by the controller to make the second clutch 02 in the engaged position, and the output pressure of the first electromagnetic valve 1, the third electromagnetic valve 3 and the fourth electromagnetic valve 4 is adjusted to make the first clutch 01, the third clutch 03 and the fork 04 all in the disengaged position, at this time, the input shaft I and the output shaft O of the transmission are driven through the steel belt, which makes the vehicle speed change more smoothly.

[0103] When reversing, the output pressure of the third electromagnetic valve 3 and the fourth electromagnetic valve 4 is adjusted by the controller to make the third clutch 03 in the engaged position, the fork 04 in the first engaged position, and the output pressure of the first electromagnetic valve 1 and the second electromagnetic valve 2 is adjusted to make the first clutch 01 and the second clutch 02 in the disengaged position, at this time, the input shaft I of the transmission is reversely driven through the first gear.

[0104] Therefore, the control device of the continuously variable transmission supports the gear direct drive type continuously variable transmission to switch between two transmission modes, which improves the transmission efficiency and starting response by gear transmission when starting or driving at low speed, and by steel belt transmission when driving at high speed.

[0105] Further, it further comprises a second gear transmission assembly, when the first clutch 01 is in the engaged position and the fork 04 is in the second engaged position, the input shaft I and the output shaft O are driven through the second gear transmission assembly, and the control system further comprises a fifth electromagnetic valve 5 for switching the engaged position of the fork 04.

[0106] In this way, when the vehicle speed is lower than the first preset vehicle speed, the fifth electromagnetic valve 5 can be adjusted by the controller to switch the fork 04 to the first engaged position, and the input shaft I and the output shaft O of the transmission are driven through the first gear transmission assembly; when the vehicle speed is higher than the second preset vehicle speed, the fifth electromagnetic valve 5 can be adjusted by the controller to switch the fork 04 to the second engaged position, and the input shaft I and the output shaft O of the transmission are driven through the second gear transmission assembly.

[0107] Please refer to Figure 8 , Figure 8A structure schematic view of one specific embodiment of the control system of the continuously variable transmission provided by the present application.

[0108] The present application also provides a control system of a continuously variable transmission, comprising:

[0109] A first electromagnetic valve 1, the output end of which is communicated with a first clutch 01;

[0110] A second electromagnetic valve 2, the output end of which is communicated with a second clutch 02;

[0111] A third electromagnetic valve 3, the output end of which is communicated with a shift fork 04;

[0112] A fourth electromagnetic valve 4, the output end of which is communicated with a third clutch 03;

[0113] A controller, used for adjusting the output end pressure of the first electromagnetic valve 1, the second electromagnetic valve 2, the third electromagnetic valve 3 and the fourth electromagnetic valve 4 according to the vehicle running state.

[0114] Here, the vehicle running state includes oil temperature signal, speed ratio change, engine speed, etc., which can be set comprehensively according to specific requirements in actual application.

[0115] The control system of the continuously variable transmission of the present application is suitable for the control device of the aforementioned continuously variable transmission, thus having the same technical effects, which will not be described here again.

[0116] The hydraulic control system is suitable for Figure 1 The gear direct drive type continuously variable transmission of the first embodiment shown.

[0117] Further, the output end of the third electromagnetic valve 3 is also communicated with the fourth electromagnetic valve 4, and the control system further comprises:

[0118] A fifth electromagnetic valve 5, the first oil port of which is connected with the output end of the third electromagnetic valve 3, the second oil port of which is communicated with an oil tank, the third oil port of which is communicated with one side cavity of the shift fork 04, the fourth oil port of which is communicated with the other side cavity of the shift fork 04, the first control end of which is an electromagnetic control end, and the second control end of which is a spring end;

[0119] In the first working position, the first oil port and the third oil port of the fifth electromagnetic valve 5 are communicated, and the second oil port and the fourth oil port are communicated; in the second working position, the first oil port and the fourth oil port of the fifth electromagnetic valve 5 are communicated, and the second oil port and the third oil port are communicated.

[0120] As set above, the hydraulic control system is suitable for Figure 4The second embodiment of the gear direct drive continuously variable transmission shown can realize gear transmission gear position switching by switching the working position of the fifth electromagnetic valve 5. Specifically, when the vehicle speed is lower than the first preset vehicle speed, the fifth electromagnetic valve 5 is controlled to be in the second working position, that is, the right cavity of the shift fork 04 is in conduction with the output end of the third electromagnetic valve 3, and the left cavity is in conduction with the oil tank. At this time, the input shaft I and the output shaft O of the transmission are transmitted through the first gear on the left side; when the vehicle speed is higher than the second preset vehicle speed, the fifth electromagnetic valve 5 is controlled to be in the first working position, that is, the left cavity of the shift fork 04 is in conduction with the output end of the third electromagnetic valve 3, and the right cavity is in conduction with the oil tank. The input shaft I and the output shaft O of the transmission are transmitted through the second gear on the right side.

[0121] Therefore, the hydraulic control system of the embodiment adds the fifth electromagnetic valve 5 to support the gear direct drive continuously variable transmission to adopt gear transmission in the low speed ratio interval and the high speed ratio interval where the steel belt transmission efficiency is low, improve the transmission efficiency, and improve the starting response.

[0122] Further, the sixth electromagnetic valve 6 is further included, the output end of the third electromagnetic valve 3 is further in communication with the sixth electromagnetic valve 6, and the output end of the sixth electromagnetic valve 6 is in communication with the parking oil cylinder 05.

[0123] The controller is further used to adjust the output end pressure of the sixth electromagnetic valve 6.

[0124] Specifically, the first oil port of the sixth electromagnetic valve 6 is in communication with the sixth electromagnetic valve 6, the second oil port is in communication with the oil tank, the third oil port is in communication with the parking oil cylinder 05, the first control end is the electromagnetic control end, the second control end is the spring end, and the second control end is further in communication with the third oil port. When the sixth electromagnetic valve 6 is in the first working position, the second oil port and the third oil port are in conduction, and when the sixth electromagnetic valve 6 is in the second working position, the first oil port and the third oil port are in conduction. Therefore, the pressure of the electromagnetic control end of the sixth electromagnetic valve 6 can be adjusted by the controller to switch the working position of the sixth electromagnetic valve 6 and park.

[0125] Further, the hydraulic control system of the embodiment further includes a switching valve 7, the first oil port of the switching valve 7 is in communication with the output end of the second electromagnetic valve 2, the second oil port is in communication with the oil tank, the third oil port is in communication with the second clutch 02, and the first control end is the spring end, and the second control end is in communication with the output end of the sixth electromagnetic valve 6.

[0126] When the switching valve 7 is in the first working position, the first oil port and the third oil port are in conduction; when the switching valve 7 is in the second working position, the second oil port and the third oil port are in conduction.

[0127] The setting of the switching valve 7 can ensure that the second clutch 02 oil supply is cut off in time through the sixth electromagnetic valve 6 when the pressure anomaly is detected.

[0128] Furthermore, it also includes a mechanical pump 8, the oil outlet of which is connected to the main oil circuit A. The main oil circuit A has branches including a first branch A1 and a second branch A2. The first solenoid valve 1 and the second solenoid valve 2 are both located in the first branch A1, and the third solenoid valve 3 is located in the second branch A2.

[0129] It also includes a pressure reducing valve 9, which is used to adjust the oil pressure of the first branch A1 to a preset pressure.

[0130] Specifically, the first port of the pressure reducing valve 9 is connected to the main oil circuit A, the second port is connected to the oil tank, and the third port is connected to the first branch A1. Its first control end is a spring end, and its second control end is connected to the third port. When the oil pressure of the first branch A1 is lower than the preset pressure, the pressure reducing valve 9 switches to the first working position, and its first port and third port are connected. The hydraulic oil from the mechanical pump 8 continues to flow to the first branch A1 until the oil pressure of the first branch A1 reaches the preset pressure. When the oil pressure of the first branch A1 is higher than the preset pressure, the pressure reducing valve 9 switches to the second working position, and its second port and third port are connected, that is, the first branch A1 is connected to the oil tank to reduce the pressure of the first branch A1 until the oil pressure of the first branch A1 is reduced to the preset pressure.

[0131] Therefore, the pressure reducing valve 9 can provide a stable input pressure for the first solenoid valve 1, the second solenoid valve 2, and other valves connected to the first branch A1 (which will be explained later). The specific value can be adjusted adaptively according to the requirements.

[0132] Meanwhile, the fourth solenoid valve 4, the fifth solenoid valve 5, and the sixth solenoid valve 6 are all connected to the second branch A2 via the third solenoid valve 3. On the one hand, they can share the overcurrent burden of the pressure reducing valve 9; on the other hand, the output pressure of the third solenoid valve 3 can be adjusted by the controller, thereby providing a stable input pressure for the fourth solenoid valve 4, the fifth solenoid valve 5, and the sixth solenoid valve 6, or actively cutting off the pressure of the actuator at the back end of the branch when the pressure is abnormal.

[0133] In this configuration, the first oil port of the first solenoid valve 1 is connected to the third oil port of the pressure reducing valve 9, the second oil port is connected to the oil tank, and the third oil port is connected to the first clutch 01. The first control end is an electromagnetic control end, the second control end is a spring end, and the second control end is also connected to the third oil port. When the first solenoid valve 1 is in the first working position, its second oil port and third oil port are connected; when it is in the second working position, its first oil port and third oil port are connected.

[0134] The first oil port of the third electromagnetic valve 3 is communicated with the second branch A2, the second oil port is communicated with the oil tank, the third oil port is communicated with the fourth electromagnetic valve 4, the fifth electromagnetic valve 5 and the sixth electromagnetic valve 6, the first control end is the electromagnetic control end, the first control end is also communicated with the third oil port, the second control end is the spring end, when the third electromagnetic valve 3 is in the first working position, the first oil port is communicated with the third oil port, when the third electromagnetic valve 3 is in the second working position, the second oil port is communicated with the third oil port.

[0135] In this way, when the vehicle speed is lower than the first preset vehicle speed, the output pressure of the first electromagnetic valve 1 and the third oil port of the third electromagnetic valve 3 can be adjusted by the controller, so that the first electromagnetic valve 1 is switched to the second working position, the third electromagnetic valve 3 is switched to the first working position, and the pressure of the electromagnetic control end of the fifth electromagnetic valve 5 is adjusted to switch the fifth electromagnetic valve 5 to the second working position, so that the transmission is driven by the first gear.

[0136] In addition, the first oil port of the second electromagnetic valve 2 is communicated with the third oil port of the pressure reducing valve 9, the second oil port is communicated with the oil tank, the third oil port is communicated with the switching valve 7, the first control end is the electromagnetic control end, the second control end is the spring end, and the second control end is also communicated with the third oil port, when the second electromagnetic valve 2 is in the first working position, the second oil port is communicated with the third oil port, and when the second electromagnetic valve 2 is in the second working position, the first oil port is communicated with the third oil port.

[0137] In this way, when the vehicle speed is between the first preset vehicle speed and the second preset vehicle speed, the output pressure of the third oil port of the second electromagnetic valve 2 can be adjusted by the controller to switch the second electromagnetic valve 2 to the second working position, and the output pressure of the third oil port of the third electromagnetic valve 3 is adjusted to switch the third electromagnetic valve 3 to the second working position, so that the second clutch 02 is in the engaged position, the first clutch 01, the third clutch 03 and the shift fork 04 are in the isolated position, and the input shaft I and the output shaft O of the transmission are driven by the steel belt.

[0138] In addition, the first oil port of the fourth electromagnetic valve 4 is communicated with the third oil port of the third electromagnetic valve 3, the second oil port is communicated with the oil tank, the third oil port is communicated with the third clutch 03, the first control end is the electromagnetic control end, the second control end is the spring end, and the second control end is also communicated with the third oil port, when the fourth electromagnetic valve 4 is in the first working position, the second oil port is communicated with the third oil port, and when the fourth electromagnetic valve 4 is in the second working position, the first oil port is communicated with the third oil port.

[0139] In this way, when reversing, the output pressure of the third oil port of the third electromagnetic valve 3 and the fourth electromagnetic valve 4 can be adjusted by the controller to switch the third electromagnetic valve 3 to the first working position and the fourth electromagnetic valve 4 to the second working position, and the third clutch 03 is in the engaged position, and the pressure of the electromagnetic control end of the fifth electromagnetic valve 5 is controlled to switch the fifth electromagnetic valve 5 to the second working position, so that the transmission is driven through the first gear.

[0140] Please continue to refer to Figure 8 In the hydraulic control system of the embodiment, the branch of the main oil path A further includes a third branch A3, the second branch A2 is further communicated with the oil inlet end of the driven oil cylinder 06, the third branch A3 is communicated with the oil inlet end of the driving oil cylinder 07, and further includes:

[0141] The driving pressure regulating valve 11 is used to adjust the hydraulic oil pressure entering the driving oil cylinder 07;

[0142] The driven pressure regulating valve 12 is used to adjust the hydraulic oil pressure entering the driven oil cylinder 06.

[0143] The driving oil cylinder 07 and the driven oil cylinder 06 are used to clamp the metal belt, and the change of the speed ratio is realized by adjusting the pressure ratio between the two; in the above setting, the pressures of the driving oil cylinder 07 and the driven oil cylinder 06 are controlled respectively, and the flexibility is good.

[0144] Further, it further includes:

[0145] The seventh electromagnetic valve 13 is communicated with the third oil port of the pressure reducing valve 9 at the first oil port, communicated with the oil tank at the second oil port, and communicated with the first control end of the driven pressure regulating valve 12 at the third oil port, the second control end of the driven pressure regulating valve 12 is the spring end, and further communicated with the oil path between the driven pressure regulating valve 12 and the driven oil cylinder 06;

[0146] The controller is further used to adjust the output pressure of the third oil port of the seventh electromagnetic valve 13.

[0147] Therefore, the working position switching of the driven pressure regulating valve 12 is controlled by the output pressure of the third oil port of the seventh electromagnetic valve 13, the spring force and the feedback pressure of the driven oil cylinder 06.

[0148] Specifically, the first oil port of the driven pressure regulating valve 12 is communicated with the second branch A2, the second oil port is communicated with the oil tank, and the third oil port is communicated with the driven oil cylinder 06, the first oil port and the third oil port are conducted at the first working position; the third oil port and the second oil port are conducted at the second working position.

[0149] After the above setting, the pressure of the driven oil cylinder 06 is controlled by the seventh electromagnetic valve 13 and the driven pressure regulating valve 12, so that Figure 8As shown, the left end of the driven pressure regulating valve 12 is acted upon by the output pressure of the third oil port of the seventh electromagnetic valve 13, and the right end is acted upon by the spring force and the feedback pressure of the driven oil cylinder 06; when the pressure of the driven oil cylinder 06 is lower than the target pressure, the controller adjusts the output pressure of the third oil port of the seventh electromagnetic valve 13, so that the driven pressure regulating valve 12 switches to the first working position, the first oil port and the third oil port of the driven pressure regulating valve 12 are communicated, at this time, the driven oil cylinder 06 is communicated with the second branch A2, until the pressure of the driven oil cylinder 06 reaches the target pressure;

[0150] When the pressure of the driven oil cylinder 06 is higher than the target pressure, the controller adjusts the output pressure of the third oil port of the seventh electromagnetic valve 13, so that the driven pressure regulating valve 12 switches to the second working position, the second oil port and the third oil port of the driven pressure regulating valve 12 are communicated, at this time, the driven oil cylinder 06 is communicated with the tank, so as to reduce the pressure of the driven oil cylinder 06, until the pressure of the driven oil cylinder 06 reaches the target pressure.

[0151] Similarly, the eighth electromagnetic valve 14 is also included, the first oil port of which is communicated with the third oil port of the pressure reducing valve 9, the second oil port of which is communicated with the tank, and the third oil port of which is communicated with the first control end of the driven pressure regulating valve 11, the second control end of which is the spring end, and is also communicated with the oil path connecting the driven pressure regulating valve 11 and the driven oil cylinder 07.

[0152] Therefore, the working position switching of the driven pressure regulating valve 11 is controlled by the output pressure of the third oil port of the eighth electromagnetic valve 14, the spring force and the feedback pressure of the driven oil cylinder 07.

[0153] Specifically, the first oil port of the driven pressure regulating valve 11 is communicated with the third branch A3, the second oil port is communicated with the tank, and the third oil port is communicated with the driven oil cylinder 06, at the first working position, the first oil port and the third oil port are communicated; at the second working position, the third oil port and the second oil port are communicated.

[0154] After the above arrangement, the pressure of the driven oil cylinder 06 is controlled by the seventh electromagnetic valve 13 and the driven pressure regulating valve 12, so that Figure 8 As shown, the left end of the driven pressure regulating valve 12 is acted upon by the output pressure of the third oil port of the seventh electromagnetic valve 13, and the right end is acted upon by the spring force and the feedback pressure of the driven oil cylinder 06; when the pressure of the driven oil cylinder 06 is lower than the target pressure, the controller adjusts the output pressure of the third oil port of the seventh electromagnetic valve 13, so that the driven pressure regulating valve 12 switches to the first working position, the first oil port and the third oil port of the driven pressure regulating valve 12 are communicated, at this time, the driven oil cylinder 06 is communicated with the second branch A2, until the pressure of the driven oil cylinder 06 reaches the target pressure;

[0155] When the pressure of the active oil cylinder 07 is higher than the target pressure, the controller adjusts the output pressure of the third oil port of the eighth electromagnetic valve 14 to make the active pressure regulating valve 11 switch to the second working position, and the second oil port and the third oil port of the active pressure regulating valve 11 are communicated, at this time, the active oil cylinder 07 is communicated with the oil tank to reduce the pressure of the active oil cylinder 07 until the pressure of the active oil cylinder 07 reaches the target pressure.

[0156] Please continue to refer to Figure 8 In the hydraulic control system of the embodiment, further comprising:

[0157] The electronic pump 15;

[0158] The electronic pump switching valve 16, the oil inlet thereof is communicated with the oil outlet of the electronic pump 15, the first oil outlet is communicated with the pressure reducing valve 9, the driven pressure regulating valve 12 and the third electromagnetic valve 3, the second oil outlet is communicated with the first cooling and lubricating branch circuit C1, and the electronic pump switching valve 16 can be switched between the first working position and the second working position according to the output pressure of the second electromagnetic valve 2: when in the first working position, the oil inlet and the first oil outlet are communicated; when in the second working position, the oil inlet and the second oil outlet are communicated;

[0159] The electronic pump pressure regulating valve 17 is used to adjust the inlet pressure of the electronic pump switching valve 16 according to the output pressures of the first electromagnetic valve 1 and the fourth electromagnetic valve 4.

[0160] Specifically, the first control end of the electronic pump switching valve 16 is the spring end, and the second control end is communicated with the third oil port of the second electromagnetic valve 2; the inlet of the electronic pump pressure regulating valve 17 is communicated with the oil outlet of the electronic pump 15, the outlet is communicated with the oil tank, the first control end is communicated with the oil outlet of the electronic pump 15, the second control end is the spring end, and is further communicated with the third oil ports of the first electromagnetic valve 1 and the fourth electromagnetic valve 4, and in the normal state, the inlet and the outlet of the electronic pump pressure regulating valve 17 are cut off.

[0161] As arranged above, the hydraulic control system of the embodiment adopts the mode of mechanical pump 8 + electronic pump 15, when the transmission is driven by gears, the electronic pump 15 provides control pressure for the actuators, and when the transmission is driven by steel belts, the mechanical pump 8 provides control pressure for the actuators.

[0162] Specifically, in the embodiment, the electronic pump 15 is used to provide control pressure for the actuators when the transmission is driven by gears, and the mechanical pump 8 is used to provide control pressure for the actuators when the transmission is driven by steel belts. Figure 8For example, when the transmission is driven by gears, the second clutch 02 is disconnected, the second solenoid valve 2 is switched to the first working position, the spring force at the left end of the electronic pump switching valve 16 is greater than the feedback pressure of the second solenoid valve 2, the electronic pump switching valve 16 is switched to the first working position, the electronic pump 15 provides control pressure for the first clutch 01 and the shift fork 04, or provides control pressure for the third clutch 03 and the shift fork 04, at the same time, the output pressure of the first clutch 01 or the third clutch 03 is fed back to the electronic pump pressure regulating valve 17, so that the output pressure of the electronic pump 15 meets the pressure requirement of the first clutch 01 or the third clutch 03. At this time, the controller can set the main oil circuit A pressure to the minimum to reduce the load of the mechanical pump 8, thereby reducing fuel consumption;

[0163] When the transmission is driven by steel belts, since the driving oil cylinder 07 and the driven oil cylinder 06 require a relatively high system pressure to achieve gear shifting and clamping, in the steel belt transmission mode, the mechanical pump 8 provides high pressure oil to control the actuator pressure, at this time the second clutch 02 pressure is fed back to the electronic pump switching valve 16, the electronic pump switching valve 16 is switched to the second working position, the flow of the electronic pump 15 is cut to the first cooling and lubrication branch C1, at the same time, the output flow of the electronic pump 15 can be adjusted according to the cooling and lubrication flow demand.

[0164] Further, two check valves 18 are further included to allow hydraulic oil to flow only from the first oil outlet of the electronic pump switching valve 16 to the pressure reducing valve 9, the driven pressure regulating valve 12 and the third solenoid valve 3.

[0165] Please continue to refer to Figure 8 In the hydraulic control system of the embodiment, the mechanical pump 8 includes a first oil outlet and a second oil outlet, both of which are connected with the main oil circuit A, and a check valve 18 is further arranged between the first oil outlet and the second oil outlet to allow hydraulic oil from the second oil outlet to flow only from the main oil circuit A, and the hydraulic control system further includes:

[0166] An oil pump switching valve 19, a first oil port of which is in communication with the first oil outlet of the mechanical pump 8, a second oil port of which is in communication with the oil tank, and when in the first working position, the first oil port and the second oil port are in communication; when in the second working position, the first oil port and the second oil port are isolated.

[0167] In this way, when the transmission is driven by the steel belt and the high-pressure oil for controlling the actuator is provided by the mechanical pump 8, the oil pump switching valve 19 can be controlled to be in the second working position, the first oil port and the second oil port are isolated, the hydraulic oil from the first oil outlet and the hydraulic oil from the second oil outlet are collected in the main oil line A, and the mechanical pump 8 is switched to the double-pump mode; when the transmission is driven by the gear and the speed is high, the oil pump switching valve 19 can be controlled to be in the first working position, the first oil port and the second oil port are communicated, the hydraulic oil from the first oil outlet returns to the oil tank, only the hydraulic oil from the second oil outlet flows to the main oil line A, and the mechanical pump 8 is switched to the single-pump mode, thereby reducing the energy consumption.

[0168] Specifically, the ninth electromagnetic valve 20 is further included, the first oil port of which is communicated with the third oil port of the pressure reducing valve 9, the second oil port is communicated with the oil tank, the third oil port is communicated with the first control end of the oil pump switching valve 19, the first control end is the electromagnetic control end, the second control end is the spring end, and the second oil port and the third oil port are communicated when the ninth electromagnetic valve 20 is in the first working position; the first oil port and the third oil port are communicated when the ninth electromagnetic valve 20 is in the second working position.

[0169] The second control end of the oil pump switching valve 19 is the spring end.

[0170] In this way, the working position of the oil pump switching valve 19 is switched by the spring force and the output pressure of the ninth electromagnetic valve 20, so that Figure 8 As shown in the figure, when the mechanical pump 8 needs to be switched to the double-pump mode, only the pressure of the electromagnetic control end of the ninth electromagnetic valve 20 needs to be controlled, so that the ninth electromagnetic valve 20 is switched to the first working position, and then the pressure of the first control end of the oil pump switching valve 19 is less than the pressure of the spring end, and the oil pump switching valve 19 is in the second working position; when the mechanical pump 8 needs to be switched to the single-pump mode, only the pressure of the electromagnetic control end of the ninth electromagnetic valve 20 needs to be controlled, so that the ninth electromagnetic valve 20 is switched to the second working position, and then the pressure of the first control end of the oil pump switching valve 19 is greater than the pressure of the spring end, and the oil pump switching valve 19 is switched to the first working position.

[0171] Please continue to refer to Figure 8 The hydraulic control system of the embodiment further includes:

[0172] The main oil line pressure regulating valve 21 is communicated with the main oil line A at the inlet, communicated with the second oil line B at the first oil outlet, and communicated with the oil tank at the second oil outlet, and when the main oil line pressure regulating valve 21 is in the first working position, the inlet, the first oil outlet and the second oil outlet are all communicated; when the main oil line pressure regulating valve 21 is in the second working position, the inlet and the first oil outlet are communicated; when the main oil line pressure regulating valve 21 is in the third working position, the inlet, the first oil outlet and the second oil outlet are all isolated.

[0173] The tenth electromagnetic valve 22 is communicated with the spring end of the main oil line pressure regulating valve 21 at the output end, and the other control end of the main oil line pressure regulating valve 21 is communicated with the inlet.

[0174] The controller is further configured to adjust the output pressure of the tenth electromagnetic valve 22.

[0175] In this way, the working position switching of the main oil passage pressure regulating valve 21 is controlled by the output pressure of the tenth electromagnetic valve 22, the spring force and the main oil passage A pressure. Specifically, when the main oil passage A pressure is lower than the preset pressure, the controller adjusts the output pressure of the tenth electromagnetic valve 22 to make the main oil passage pressure regulating valve 21 switch to the third working position, and the hydraulic oil from the mechanical pump 8 flows to the main oil passage A; when the main oil passage A pressure is higher than the preset pressure, the controller adjusts the output pressure of the tenth electromagnetic valve 22 to make the main oil passage pressure regulating valve 21 switch to the second working position, and the hydraulic oil from the mechanical pump 8 flows to the secondary oil passage B; and when the secondary oil passage B pressure has also reached the preset pressure, the controller adjusts the output pressure of the tenth electromagnetic valve 22 to make the main oil passage pressure regulating valve 21 switch to the first working position, and the hydraulic oil from the mechanical pump 8 flows back to the oil tank.

[0176] Further, the hydraulic control system further comprises a main oil passage safety valve 10, the oil inlet of the main oil passage safety valve 10 is communicated with the main oil passage A, the oil outlet is communicated with the oil tank, the first control end is communicated with the main oil passage A, the second control end is the spring end, and the second control end is further communicated with the third oil port of the pressure reducing valve 9, and under normal circumstances, the oil inlet of the main oil passage safety valve 10 is cut off from the oil outlet.

[0177] Therefore, the working state of the main oil passage safety valve 10 is determined by the pressure difference between the main oil passage A and the first branch passage A1 and the spring force, so that Figure 4 For example, when the system is normal, the pressure difference between the main oil passage A and the first branch passage A1 is smaller than the spring force, the oil inlet of the main oil passage safety valve 10 is cut off from the oil outlet; when the system fails, the pressure difference between the main oil passage A and the first branch passage A1 is greater than the spring force, the oil inlet of the main oil passage safety valve 10 is communicated with the oil outlet to release pressure, so as to ensure the stability of the system pressure.

[0178] Further, the hydraulic control system further comprises:

[0179] The torque converter reversing valve 23, the first oil port of which is communicated with the first oil outlet of the main oil passage pressure regulating valve 21 through the secondary oil passage B, the second oil port is communicated with the oil tank, the third oil port is communicated with the locking cavity 081 of the hydraulic torque converter 08, the fourth oil port is communicated with the second cooling and lubricating branch passage C2, and the fifth oil port is communicated with the unlocking cavity 082 of the hydraulic torque converter 08;

[0180] The torque converter pressure regulating valve 24, the first oil port of which is communicated with the third oil port of the pressure reducing valve 9, the second oil port is communicated with the sixth oil port of the torque converter reversing valve 23, the third oil port is communicated with the oil tank, and when the torque converter pressure regulating valve 24 is located at the first working position, the second oil port is communicated with the third oil port; when the torque converter pressure regulating valve 24 is located at the second working position, the first oil port is communicated with the second oil port.

[0181] The torque converter reversing valve 23 can be switched between an unlocking position or a locking position, specifically: when the torque converter reversing valve 23 is in the unlocking position state, the third oil port of the torque converter reversing valve 23 is communicated with the fourth oil port, the first oil port is communicated with the fifth oil port, and the second oil port is communicated with the sixth oil port, in combination with the first to fifth oil ports of the torque converter regulating valve 24, the first oil port of the torque converter regulating valve 24 is communicated with the second oil port, and the third oil port of the torque converter regulating valve 24 is communicated with the first oil port of the torque converter reversing valve 23, so that the hydraulic oil in the first oil port of the torque converter regulating valve 24 flows into the unlocking cavity 082 of the torque converter 08 through the first oil port of the torque converter regulating valve 24, and then flows into the second cooling and lubricating branch C2 through the locking cavity 081 of the torque converter 08. Figure 4 It can be understood that in this state, the hydraulic oil in the secondary oil circuit B enters the second cooling and lubricating branch C2 through the first oil port, and the locking cavity 081 of the torque converter 08 is communicated with the second oil port of the torque converter regulating valve 24, and the unlocking cavity 082 of the torque converter 08 is communicated with the oil tank, at this time, the torque converter 08 is in the unlocking state.

[0182] When the torque converter reversing valve 23 is in the locking position state, the sixth oil port of the torque converter reversing valve 23 is communicated with the third oil port, the first oil port is communicated with the fourth oil port, and the fifth oil port is communicated with the second oil port, in combination with the first to fifth oil ports of the torque converter regulating valve 24, the first oil port of the torque converter regulating valve 24 is communicated with the second oil port, and the third oil port of the torque converter regulating valve 24 is communicated with the first oil port of the torque converter reversing valve 23, so that the hydraulic oil in the first oil port of the torque converter regulating valve 24 directly enters the second cooling and lubricating branch C2 through the first oil port of the torque converter regulating valve 24, and the locking cavity 081 of the torque converter 08 is communicated with the second oil port of the torque converter regulating valve 24, and the unlocking cavity 082 of the torque converter 08 is communicated with the oil tank, at this time, the torque converter 08 is in the locking state. Figure 4 It can be understood that in this state, the hydraulic oil in the secondary oil circuit B directly enters the second cooling and lubricating branch C2, the locking cavity 081 of the torque converter 08 is communicated with the second oil port of the torque converter regulating valve 24, and the unlocking cavity 082 of the torque converter 08 is communicated with the oil tank, at this time, the torque converter 08 is in the locking state.

[0183] At the same time, when the torque converter 08 is in the locking state, the locking pressure thereof is controlled through the torque converter regulating valve 24, specifically: when the locking pressure of the torque converter 08 is lower than the target pressure, the torque converter regulating valve 24 can be controlled to be in the second working position, the first oil port and the second oil port thereof are communicated, at this time, the locking cavity 081 of the torque converter 08 is communicated with the first branch A1, until the locking pressure of the torque converter 08 reaches the target pressure; when the locking pressure of the torque converter 08 is greater than the target pressure, the torque converter regulating valve 24 can be controlled to be in the first working position, the third oil port and the second oil port thereof are communicated, at this time, the locking cavity 081 of the torque converter 08 is communicated with the oil tank, so as to reduce the locking pressure, until the locking pressure of the torque converter 08 reaches the target pressure.

[0184] Further, it further comprises:

[0185] The first oil port of the eleventh electromagnetic valve 25 is communicated with the first branch A1, the second oil port is communicated with the oil tank, and the third oil port is respectively communicated with the first control end of the torque converter reversing valve 23 and the first control end of the torque converter regulating valve 24;

[0186] The second control end of the torque converter reversing valve 23 is the spring end, that is, the working position switching of the torque converter reversing valve 23 is controlled by the spring force and the output pressure of the third oil port of the eleventh electromagnetic valve 25;

[0187] The second control end of the torque converter pressure regulating valve 24 is a spring end, and also communicates with the second oil port of the torque converter pressure regulating valve 24, that is, the working position switching of the torque converter pressure regulating valve 24 is controlled by the spring force, the output pressure of the third oil port of the eleventh electromagnetic valve 25, and the lock pressure.

[0188] The eleventh electromagnetic valve 25 is arranged so that the torque converter reversing valve 23 and the torque converter pressure regulating valve 24 can be dynamically controlled.

[0189] Please continue to refer to ​ Further comprising an oil cooler 26, a filter 27 and a nozzle 28 connected in sequence, the first cooling lubrication branch C1 and the second cooling lubrication branch C2 are respectively provided with a one-way valve 18, so that the hydraulic oil is unidirectionally collected in the oil cooler 26, and the steel belt, the clutch and other components are lubricated through the filter 27 and the nozzle 28.

[0190] In addition, a safety valve 29 is further arranged on the two-stage oil circuit B and between the electronic pump 15 and the electronic pump switching valve 16, and when the system pressure is abnormal, the safety valve 29 can be used for pressure relief.

[0191] The application provides a control method of a gear direct drive type continuously variable transmission, comprising the following steps:

[0192] When the vehicle is in a forward state and the vehicle speed is lower than a first preset vehicle speed, the first clutch 01 is controlled to be in an engaged position, the shift fork 04 is controlled to be in a first engaged position, and the input shaft I and the output shaft O of the gear direct drive type continuously variable transmission are driven through a first gear transmission assembly.

[0193] When the vehicle is in a forward state and the vehicle speed is higher than the first preset vehicle speed, the second clutch 02 is controlled to be in an engaged position, and the input shaft I and the output shaft O are driven through a steel belt transmission assembly.

[0194] When the vehicle is in a reverse state, the third clutch 03 is controlled to be in an engaged position, the shift fork 04 is controlled to be in a first engaged position, and the input shaft I reversely drives the output shaft O through the first gear transmission assembly.

[0195] The control method of the gear direct drive type continuously variable transmission is suitable for the control device of the continuously variable transmission, and has the same technical effects as the control device of the continuously variable transmission, which will not be described here.

[0196] The application further provides a control method of a gear direct drive type continuously variable transmission, comprising the following steps:

[0197] When the vehicle is in a forward state and the vehicle speed is lower than a first preset vehicle speed, the first clutch 01 is controlled to be in an engaged position, the shift fork 04 is controlled to be in a first engaged position, and the input shaft I and the output shaft O of the gear direct drive type continuously variable transmission are driven through a first gear transmission assembly.

[0198] When the vehicle is moving forward and the speed is between the first preset speed and the second preset speed, the second clutch 02 is engaged, and the input shaft I and the output shaft O are driven by a steel belt.

[0199] When the vehicle is moving forward and the speed is higher than the second preset speed, the first clutch 01 is engaged, the shift fork 04 is engaged, and the input shaft I and output shaft O are driven by the two-speed gear transmission assembly.

[0200] When reversing, the third clutch 03 is engaged, the shift fork 04 is engaged, and the input shaft I drives the output shaft O in reverse through the first gear transmission assembly.

[0201] The control method of the gear direct drive continuously variable transmission of the present invention is applicable to the control equipment of the aforementioned continuously variable transmission, and therefore has the same technical effect as the control equipment of the aforementioned continuously variable transmission, which will not be repeated here.

[0202] The control system, control device, and control method of a continuously variable transmission (CVT) provided by this invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A control system for a continuously variable transmission, characterized by, The utility model relates to a kind of hydraulic control system of vehicle, including: First solenoid valve (1), its output end is communicated with first clutch (01); Second solenoid valve (2), its output end is communicated with second clutch (02); Third solenoid valve (3), its output end is communicated with yoke (04); Fourth solenoid valve (4), its output end is communicated with third clutch (03); Controller, for adjusting the output end pressure of first solenoid valve (1), second solenoid valve (2), third solenoid valve (3) and fourth solenoid valve (4) according to vehicle operating state; The output end of the third solenoid valve (3) is also communicated with the fourth solenoid valve (4), further comprising: Fifth solenoid valve (5), the first oil port of the fifth solenoid valve (5) is connected with the output end of the third solenoid valve (3), the second oil port is communicated with oil tank, the third oil port is communicated with one side cavity of the yoke (04), the fourth oil port is communicated with the other side cavity of the yoke (04), the first control end is electromagnetic control end, and the second control end is spring end; When the fifth solenoid valve (5) is located in first working position, the first oil port of the fifth solenoid valve (5) is communicated with the third oil port, and the second oil port is communicated with the fourth oil port;When second working position, the first oil port of the fifth solenoid valve (5) is communicated with the fourth oil port, and the second oil port is communicated with the third oil port; Further comprising sixth solenoid valve (6), the output end of the third solenoid valve (3) is also communicated with the sixth solenoid valve (6), and the output end of the sixth solenoid valve (6) is communicated with parking oil cylinder (05); The controller is further used for adjusting the output end pressure of the sixth solenoid valve (6); Further comprising mechanical pump (8), the oil outlet of the mechanical pump (8) is communicated with main oil way (A), and the branch of the main oil way (A) includes first branch (A1) and second branch (A2), and the first solenoid valve (1) and the second solenoid valve (2) are both arranged in the first branch (A1), and the third solenoid valve (3) is arranged in the second branch (A2); Further comprising pressure reducing valve (9), for adjusting the oil pressure of the first branch (A1) to preset pressure.

2. The control system for a continuously variable transmission according to claim 1, characterized by Further comprising switching valve (7), the first oil port of the switching valve (7) is communicated with the output end of the second solenoid valve (2), the second oil port is communicated with oil tank, the third oil port is communicated with the second clutch (02), and the first control end is spring end, and the second control end is communicated with the output end of the sixth solenoid valve (6); When the switching valve (7) is located in first working position, the first oil port and the third oil port are communicated;When second working position, the second oil port is communicated with the third oil port.

3. The control system for the continuously variable transmission according to claim 1, characterized by, The first oil port of the pressure reducing valve (9) is communicated with the main oil way (A), the second oil port is communicated with oil tank, the third oil port is communicated with the first branch (A1), the first control end is spring end, and the second control end is communicated with its third oil port; When the pressure reducing valve (9) is located in first working position, the first oil port and the third oil port are communicated;When second working position, the second oil port is communicated with the third oil port.

4. The control system for a continuously variable transmission according to claim 3, wherein The branch of the main oil path (A) further comprises a third branch (A3), the second branch (A2) is communicated with the oil inlet end of the driven oil cylinder (06), the third branch (A3) is communicated with the oil inlet end of the driving oil cylinder (07), and further comprising: A driving pressure regulating valve (11) is used for adjusting the hydraulic oil pressure entering the driving oil cylinder (07); A driven pressure regulating valve (12) is used for adjusting the hydraulic oil pressure entering the driven oil cylinder (06).

5. The control system for a continuously variable transmission according to claim 4, wherein Further comprising a seventh electromagnetic valve (13), the first oil port of which is communicated with the third oil port of the pressure reducing valve (9), the second oil port is communicated with the oil tank, and the third oil port is communicated with the first control end of the driven pressure regulating valve (12), the second control end of the driven pressure regulating valve (12) is the spring end, and further communicated with the oil path between the driven pressure regulating valve (12) and the driven oil cylinder (06); The controller is further used for adjusting the output pressure of the third oil port of the seventh electromagnetic valve (13).

6. The control system for a continuously variable transmission according to claim 4, wherein Further comprising an eighth electromagnetic valve (14), the first oil port of which is communicated with the third oil port of the pressure reducing valve (9), the second oil port is communicated with the oil tank, and the third oil port is communicated with the first control end of the driving pressure regulating valve (11), the second control end of the driving pressure regulating valve (11) is the spring end, and further communicated with the oil path between the driving pressure regulating valve (11) and the driving oil cylinder (07); The controller is further used for adjusting the output pressure of the third oil port of the eighth electromagnetic valve (14).

7. The control system for a continuously variable transmission according to claim 4, wherein Further comprising: An electronic pump (15); An electronic pump switching valve (16), the oil inlet port of which is communicated with the oil outlet port of the electronic pump (15), the first oil outlet port is communicated with the pressure reducing valve (9), the driven pressure regulating valve (12) and the third electromagnetic valve (3), the second oil outlet port is communicated with the first cooling and lubricating branch (C1), and the electronic pump switching valve (16) can be switched between the first working position and the second working position according to the output end pressure of the second electromagnetic valve (2): in the first working position, the oil inlet port is communicated with the first oil outlet port; in the second working position, the oil inlet port is communicated with the second oil outlet port; An electronic pump pressure regulating valve (17) is used for adjusting the oil inlet pressure of the electronic pump switching valve (16) according to the output end pressure of the first electromagnetic valve (1) and the fourth electromagnetic valve (4).

8. The control system for a continuously variable transmission according to claim 7, wherein Further comprising two check valves (18) to make the hydraulic oil only unidirectionally flow from the first oil outlet port of the electronic pump switching valve (16) to the pressure reducing valve (9), the driven pressure regulating valve (12) and the third electromagnetic valve (3).

9. The control system for a continuously variable transmission according to claim 8, wherein, The mechanical pump (8) comprises a first oil outlet port and a second oil outlet port, both of which are connected with the main oil path (A), and a check valve (18) is further arranged between the first oil outlet port and the second oil outlet port to make the hydraulic oil from the second oil outlet port only unidirectionally flow to the main oil path (A), and further comprising: An oil pump switching valve (19), the first oil port of which is communicated with the first oil outlet port of the mechanical pump (8), the second oil port is communicated with the oil tank, and in the first working position, the first oil port and the second oil port are communicated; in the second working position, the first oil port and the second oil port are isolated.

10. The control system for a continuously variable transmission according to claim 9, wherein, Further comprising: A ninth solenoid valve (20) has a first oil port communicated with a third oil port of the pressure reducing valve (9), a second oil port communicated with an oil tank, a third oil port communicated with a first control end of the oil pump switching valve (19), and a first control end of the ninth solenoid valve (20) is an electromagnetic control end, and a second control end is a spring end; When the ninth solenoid valve (20) is in the first working position, the second oil port and the third oil port are communicated; when the ninth solenoid valve (20) is in the second working position, the first oil port and the third oil port are communicated; The second control end of the oil pump switching valve (19) is a spring end.

11. The control system for a continuously variable transmission according to claim 10, wherein, Further comprising: A main oil path pressure regulating valve (21) has an oil inlet communicated with the main oil path (A), a first oil outlet communicated with the secondary oil path (B), and a second oil outlet communicated with the oil tank, and when the main oil path pressure regulating valve (21) is in the first working position, the oil inlet is communicated with the first oil outlet and the second oil outlet; when the main oil path pressure regulating valve (21) is in the second working position, the oil inlet is communicated with the first oil outlet; when the main oil path pressure regulating valve (21) is in the third working position, the oil inlet, the first oil outlet and the second oil outlet are all disconnected; A tenth solenoid valve (22) has an output end communicated with a spring end of the main oil path pressure regulating valve (21), and the other control end of the main oil path pressure regulating valve (21) is communicated with the oil inlet; The controller is further used for adjusting the output end pressure of the tenth solenoid valve (22).

12. The control system for a continuously variable transmission according to claim 11, wherein, Further comprising: A main oil path safety valve (10) has an oil inlet communicated with the oil inlet of the main oil path pressure regulating valve (21), an oil outlet communicated with the oil tank, a first control end communicated with the main oil path (A), a second control end as a spring end, and further communicated with a third oil port of the pressure reducing valve (9), and under normal circumstances, the oil inlet of the main oil path safety valve (10) is disconnected with the oil outlet.

13. The control system for a continuously variable transmission according to claim 11, wherein, Further comprising: A torque converter reversing valve (23) has a first oil port communicated with the first oil outlet of the main oil path pressure regulating valve (21) through the secondary oil path (B), a second oil port communicated with the oil tank, a third oil port communicated with a locking cavity (081) of the torque converter, a fourth oil port communicated with a second cooling and lubricating branch (C2), and a fifth oil port communicated with an unlocking cavity (082) of the torque converter; A torque converter pressure regulating valve (24) has a first oil port communicated with the third oil port of the pressure reducing valve (9), a second oil port communicated with a sixth oil port of the torque converter reversing valve (23), and a third oil port communicated with the oil tank, and when the torque converter pressure regulating valve (24) is in the first working position, the second oil port and the third oil port are communicated; when the torque converter pressure regulating valve (24) is in the second working position, the first oil port and the second oil port are communicated; When the torque converter reversing valve (23) is in the unlocking position state, the third oil port and the fourth oil port of the torque converter reversing valve (23) are communicated, and the first oil port and the fifth oil port are communicated; when the torque converter reversing valve (23) is in the locking position state, the sixth oil port of the torque converter reversing valve (23) is communicated with the third oil port, the first oil port is communicated with the fourth oil port, and the fifth oil port is communicated with the second oil port.

14. A control system for a continuously variable transmission according to claim 13, characterised in that, Further comprising: Eleventh solenoid valve (25), its first oil port is communicated with the first branch (A1), the second oil port is communicated with the oil tank, the third oil port is communicated with the first control end of the torque converter reversing valve (23) and the first control end of the torque converter pressure regulating valve (24) respectively; The second control end of the torque converter reversing valve (23) is a spring end; The second control end of the torque converter pressure regulating valve (24) is a spring end, and is also communicated with the second oil port of the torque converter pressure regulating valve (24); The controller is also used for adjusting the output pressure of the third oil port of the eleventh solenoid valve (25).

15. The control system for a continuously variable transmission according to claim 13, wherein, It also includes an oil cooler (26), a filter (27) and a nozzle (28) connected in sequence, the first cooling and lubricating branch (C1) and the second cooling and lubricating branch (C2) are respectively provided with a check valve (18) to make the hydraulic oil unidirectionally converge in the oil cooler (26).

16. The control system for a continuously variable transmission of claim 11 wherein, It also includes a safety valve (29) arranged on the second oil circuit (B) and between the electronic pump (15) and the electronic pump switching valve (16).

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