Hydraulic supply device

Abstract

The hydraulic supply device of the present invention enables rapid actuation of a check valve. The device comprises: a first oil pump that supplies oil to a supply passage; a second oil pump that is driven together with the first oil pump or when the first oil pump is stopped; a first check valve disposed in a first oil passage connecting the suction side of the second oil pump and the oil source, and closing the first oil passage when the second oil pump is stopped; a second check valve disposed in a second oil passage connecting the discharge side of the second oil pump and the supply passage, and closing the second oil passage when the second oil pump is stopped; and a third oil passage into which oil supplied to the supply passage flows, with the oil flowing into the third oil passage being used as auxiliary pressure for actuating the second check valve when closing the second oil passage.

Description

Technical Field

[0001] The present invention relates to an oil pressure supply device. Background Art

[0002] The hydraulic supply device supplies hydraulic oil to hydraulic working machines such as automatic transmissions. The hydraulic supply device includes a mechanical oil pump driven by the driving force of the engine and an electric oil pump driven by the driving force of the electric motor (for example, see Patent Document 1). The oil discharged by the mechanical oil pump and the electric oil pump is supplied to the main pressure (line pressure) oil circuit. The oil in the main pressure oil circuit is regulated in the pressure regulating circuit and supplied as hydraulic oil to the hydraulic working machine. If the oil supply from the mechanical oil pump stops or the oil supply is insufficient, the electric oil pump is temporarily driven.

[0003] Check valves are installed in the oil circuits on the suction and discharge sides of the electric oil pump. When the electric oil pump is stopped, the oil pressure supply device closes the oil circuits with the check valves to prevent the backflow of oil from the mechanical oil pump.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-79992

[0007] Problems to be solved by the invention

[0008] In a hydraulic pressure supply device, when the electric oil pump is stopped, it is required to quickly operate the check valve to close the oil passage. Summary of the Invention

[0009] A hydraulic supply device according to one embodiment of the present invention is a device having a supply path for supplying hydraulic oil to a hydraulic working machine, and includes:

[0010] a first oil pump that supplies oil sucked from an oil source to the supply passage;

[0011] a second oil pump that is driven together with the first oil pump or when the first oil pump is stopped, and supplies oil sucked from the oil source to the supply passage;

[0012] a first check valve provided in a first oil passage connecting the suction side of the second oil pump and the oil source, and closing the first oil passage when the second oil pump stops;

[0013] a second check valve provided in a second oil passage connecting the discharge side of the second oil pump and the supply passage, and closing the second oil passage when the second oil pump stops;

[0014] a third oil passage connected to the supply passage, into which the oil supplied to the supply passage flows;

[0015] The oil supplied from the first oil pump and flowing into the third oil passage is used as assist pressure for operating the second check valve when closing the second oil passage.

[0016] Effects of the Invention

[0017] According to one aspect of the present invention, when the electric oil pump is stopped, the check valve can be quickly actuated to close the oil passage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of a belt-type continuously variable transmission with a hydraulic pressure supply device.

[0019] Figure 2 It is a diagram schematically showing the structure of a hydraulic pressure supply device.

[0020] Figure 3 This is a diagram illustrating the specific structure of a check valve provided in an oil passage.

[0021] Figure 4 yes Figure 3 Magnified view of the area around the check valve.

[0022] Figure 5 This is a diagram illustrating the specific structure of a check valve provided in an oil passage.

[0023] Figure 6 This is a diagram explaining the operation of the check valve when the electric oil pump is operating.

[0024] Figure 7 This is a diagram explaining the operation of the check valve when the electric oil pump is stopped.

[0025] Figure 8 It is a diagram showing a comparative example. DETAILED DESCRIPTION

[0026] Hereinafter, an embodiment of one aspect of the present invention will be described with reference to the drawings.

[0027] In the embodiment, a hydraulic supply device for supplying hydraulic oil to a hydraulic working machine installed in a vehicle is described as an example. In addition, a belt-type continuously variable transmission as a transmission for a vehicle is described as an example of the hydraulic working machine.

[0028] Figure 1 It is a schematic structural diagram of a belt-type continuously variable transmission 1 including a hydraulic pressure supply device 2 .

[0029] Figure 2 It is a diagram schematically showing the structure of the hydraulic supply device 2.

[0030] like Figure 1As shown, a belt-type continuously variable transmission 1 for a vehicle includes a pair of pulleys, namely a primary pulley P1 and a secondary pulley P2, as a speed change mechanism. The belt-type continuously variable transmission 1 also includes an endless belt B wound around the pair of pulleys.

[0031] In the belt-type continuously variable transmission 1, the winding radius of the belt B on the primary pulley P1 and the secondary pulley P2 is changed, thereby changing the speed ratio of the rotation transmitted between the primary pulley P1 and the secondary pulley P2.

[0032] The primary pulley P1 and the secondary pulley P2 are provided with oil chambers R1 and R2, respectively. By adjusting the pressure of the hydraulic oil supplied to the oil chambers R1 and R2, the winding radius of the belt B on the primary pulley P1 and the secondary pulley P2 is changed.

[0033] The belt-type continuously variable transmission 1 includes a hydraulic pressure supply device 2. This device includes a mechanical oil pump 3 (first oil pump) and an electric oil pump 4 (second oil pump). The hydraulic pressure supply device 2 regulates the pressure of the oil discharged from the mechanical oil pump 3 and the electric oil pump 4 via a pressure regulating circuit 70. The pressure regulating circuit 70 supplies the regulated oil as hydraulic oil to the oil chambers R1 and R2.

[0034] The mechanical oil pump 3 is driven by rotation input from a vehicle drive source such as an engine. The mechanical oil pump 3 switches between operation and stop in conjunction with the operation and stop of the vehicle drive source. The electric oil pump 4 is driven by rotation input from an electric motor provided separately from the vehicle drive source. The electric oil pump 4 switches between operation and stop by the control unit CU switching the operation and stop of the electric motor.

[0035] The electric oil pump 4 is driven when the oil supply from the mechanical oil pump 3 stops, that is, when the mechanical oil pump 3 stops. Alternatively, the electric oil pump 4 is driven together with the mechanical oil pump 3 when the oil supply from the mechanical oil pump 3 is insufficient. The electric oil pump 4 can also operate in place of the mechanical oil pump 3 when the mechanical oil pump 3 stops, such as when the vehicle is idling. Alternatively, the electric oil pump 4 can be operated in conjunction with the mechanical oil pump 3 when a high oil pressure is required, such as when downshifting the belt-type continuously variable transmission 1.

[0036] like Figure 2 As shown, the belt-type continuously variable transmission 1 includes a transmission case 5 that houses a speed change mechanism. An oil pan 6 is provided below the transmission case 5 in the direction of a vertical line VL, storing oil OL. Here, the vertical line VL refers to the direction of the vertical line relative to the state in which the belt-type continuously variable transmission 1 is mounted on a vehicle. The oil pan 6 covers the lower opening of the transmission case 5. An oil reservoir PL, serving as an oil source, is formed within the oil pan 6. The mechanical oil pump 3 and the electric oil pump 4 draw oil OL from the oil reservoir PL.

[0037] When the vehicle with the belt-type continuously variable transmission 1 is traveling forward, the oil OL within the oil pan 6 tends to shift toward the rear side in the vehicle's longitudinal direction. Therefore, the oil pan 6, mounted on the transmission case 5, is tilted so that it becomes positioned upward as it moves from the rear end toward the front end in the vehicle's longitudinal direction. This tilt causes the oil reservoir PL to be deeper on the rear side of the vehicle than on the front side. In other words, more oil OL is stored within the oil pan 6 on the rear side of the vehicle than on the front side.

[0038] A control valve body 7 is arranged inside the oil pan 6. The control valve body 7 is fixed to the lower part of the transmission case 5. Although not shown in the figure, the control valve body 7 is composed of an upper valve body and a lower valve body with a partition plate sandwiched between them. A pressure regulating circuit 70 (see Figure 1 ).

[0039] A filter 8 is fixed to the lower portion of the control valve body 7. The filter 8 has a suction port 81 for the oil OL at the lower portion. The filter 8 has a filter F inside for filtering the oil OL.

[0040] The mechanical oil pump 3 and the electric oil pump 4 are arranged above the filter 8 in the direction of the vertical line VL. Figure 2 In the figure, the mechanical oil pump 3 and the electric oil pump 4 are schematically shown in a circle to facilitate understanding of their positional relationship. The suction ports 31 and 41 of the mechanical oil pump 3 and the electric oil pump 4 are also schematic diagrams showing only their positions.

[0041] The mechanical oil pump 3 and the electric oil pump 4 are connected to the control valve body 7 through the oil passages 21 and 22 (see Figure 1 ) is connected to the filter 8. The mechanical oil pump 3 and the electric oil pump 4 suck the oil OL stored in the oil pan 6 through the filter 8.

[0042] The oil OL sucked in by the mechanical oil pump 3 and the electric oil pump 4 is supplied from the respective discharge ports 32 and 42 via the oil passages 23 and 24 to the pressure regulating circuit 70 .

[0043] like Figure 1 As shown, check valves 91, 92, 93 for opening and closing the oil passages are provided in the oil passages 22, 23, 24, respectively.

[0044] Check valve 92 closes oil passage 23 when mechanical oil pump 3 stops, preventing the backflow of oil OL discharged from electric oil pump 4. Check valves 91 and 93 close oil passages 22 and 24 when electric oil pump 4 stops, preventing the backflow of oil OL discharged from mechanical oil pump 3. The detailed structure and operation of the check valves will be described later.

[0045] like Figure 2As shown, the mechanical oil pump 3 is positioned near the rear end of the filter 8 in the vehicle's longitudinal direction. The electric oil pump 4 is positioned near the front end of the filter 8 in the vehicle's longitudinal direction. The mechanical oil pump 3 and the electric oil pump 4 are arranged along parallel line segments X1 and X2. The mechanical oil pump 3 and the electric oil pump 4 are positioned above the inclined filter 8. Therefore, the straight line La, which is perpendicular to the line segments X1 and X2, is inclined at an angle θ relative to the horizontal line HL.

[0046] Due to this inclination, the lower portion of the mechanical oil pump 3, which is located near the rear end of the filter 8, is located in the liquid within the oil reservoir PL. On the other hand, the lower portion of the electric oil pump 4, which is located near the front end of the filter 8, is sometimes located in the air above the liquid level of the oil reservoir PL.

[0047] like Figure 1 As shown, the mechanical oil pump 3 and the electric oil pump 4 are provided with suction ports 31 and 41 for oil OL, respectively. The filter 8 is provided with connection ports 82 and 83. The suction ports 31 and 41 and the connection ports 82 and 83 are connected via oil passages 21 and 22, respectively.

[0048] like Figure 2 As shown, due to the inclination of the filter 8, the suction port 31 provided at the bottom of the mechanical oil pump 3 is located in the liquid of the oil reservoir PL. The suction port 41 provided at the bottom of the electric oil pump 4 is sometimes located in the air. Figure 1 This is a schematic diagram, and for convenience, the suction port 31 of the mechanical oil pump 3 is also shown above the oil reservoir PL.

[0049] The pressure regulating circuit 70 is formed in the control valve body 7 (refer to Figure 2 ) inside. Figure 1 As shown, the pressure regulating circuit 70 includes a line pressure oil circuit 71 (supply circuit) connected to oil circuits 23 and 24. The oil pressure generated by the mechanical oil pump 3 and the electric oil pump 4 is input to the line pressure oil circuit 71 as the initial pressure of the line pressure (line pressure). The pressure regulating circuit 70 includes electromagnetic coils (solenoids) 76a and 76b for regulating the line pressure and pressure regulating valves 72 to 75. The electromagnetic coils 76a and 76b are driven based on commands (energization) from the control unit CU. The pressure regulating valves 72 to 75 are actuated by, for example, signal pressure generated by the electromagnetic coils 76a and 76b.

[0050] The first pressure regulating valve 72 regulates the line pressure input to the line pressure oil passage 71 by regulating the discharge amount of the oil OL. In addition, the first pressure regulating valve 72 supplies a portion of the oil OL to the transmission case 5 (see FIG. 1 ) as lubricating oil for lubricating the components of the belt-type continuously variable transmission 1. Figure 2 )Inside.

[0051] The line pressure regulated by the first pressure regulating valve 72 is supplied to the second pressure regulating valve 73 , the primary pressure regulating valve 74 , and the secondary pressure regulating valve 75 .

[0052] The second pressure regulating valve 73 regulates the pilot pressure according to the main pressure.

[0053] The pilot pressure regulated by the second pressure regulating valve 73 is supplied to the electromagnetic coil 76 a on the primary pulley P1 side and the electromagnetic coil 76 b on the secondary pulley P2 side.

[0054] The electromagnetic coils 76a and 76b are connected to the primary pressure regulating valve 74 and the secondary pressure regulating valve 75, respectively. The electromagnetic coils 76a and 76b are controlled by the control unit CU. The electromagnetic coils 76a and 76b adjust the supplied pilot pressure to a signal pressure, which is then supplied to the primary pressure regulating valve 74 and the secondary pressure regulating valve 75.

[0055] The primary pressure regulating valve 74 and the secondary pressure regulating valve 75 regulate the line pressure supplied from the first pressure regulating valve 72 to a working pressure according to the signal pressure. The oil OL regulated to the working pressure is supplied to the oil chambers R1 and R2 as working oil.

[0056] The pressure regulating circuit 70 includes an oil passage 77 (third oil passage) connected to the line pressure oil passage 71. Oil passage 77 branches off from the connection between the line pressure oil passage 71 and the oil passages 23 and 24 and the first pressure regulating valve 72. Oil OL flows from the line pressure oil passage 71 into oil passage 77. Specifically, the line pressure, which becomes the initial pressure before regulation by the first pressure regulating valve 72, is input from the line pressure oil passage 71 to oil passage 77. Oil passage 77 allows the input line pressure to act on the aforementioned check valve 93. Details of oil passage 77 and the structure of the check valve 93 will be described later.

[0057] Figure 3 This is a diagram illustrating a specific structure of the check valve 93 provided in the oil passage 24 .

[0058] Figure 4 yes Figure 3 An enlarged view of the area around the check valve 93.

[0059] In the following description, the “oil feeding direction” refers to a direction in which the oil OL is fed from the oil reservoir PL to the pressure regulating circuit 70 by suction of the electric oil pump 4 . Figure 3 The end portion 24 a on the upstream side in the oil conveying direction of the oil passage 24 (hereinafter simply referred to as “the end portion 24 a ”) is connected to the discharge port 42 of the electric oil pump 4 .

[0060] like Figure 3 As shown, the oil passage 24 is mainly formed inside the control valve body 7, but the end portion 24a is formed inside the wall portion 51 of the transmission case 5. The wall portion 51 extends from the transmission case 5 toward the control valve body 7 side.

[0061] The control valve body 7 is provided with a cylindrical wall portion 78 that surrounds the outer periphery of the oil passage 24. The front end portion 511 of the wall portion 51 is fitted into the outer periphery of the front end of the cylindrical wall portion 78. This allows the inner periphery of the cylindrical wall portion 78 to communicate with the interior of the wall portion 51. The oil passage 24 is connected to the interior of the control valve body 7 from the end portion 24a formed inside the wall portion 51.

[0062] The wall portion 51 has a circular opening 51a. The opening 51a is formed so as to penetrate the wall portion 51 in the thickness direction. The opening 51a connects the discharge port 42 of the electric oil pump 4 with the end 24a of the oil passage 24. The opening direction of the opening 51a is perpendicular to the axis Y direction. The axis Y direction is the direction in which the oil passage 24 extends within the control valve body 7. In the figure, the "opening direction" refers to the axis X3 direction, which passes through the center of the opening 51a and is perpendicular to the opening surface of the opening 51a.

[0063] like Figure 4 As shown, a cylindrical peripheral wall portion 54 is provided on the outer periphery of the opening portion 51a, surrounding the opening portion 51a. The peripheral wall portion 54 has an inner diameter D2 that is larger than the opening diameter D1 of the opening portion 51a. A cylindrical gasket 55 and a sealing ring 56 are provided inside the peripheral wall portion 54. The opening 55a of the gasket 55 and the opening 56a of the sealing ring 56 are arranged so as to be aligned with the opening direction of the opening portion 51a.

[0064] The seal ring 56 is located on the electric oil pump 4 side of the gasket 55 . The seal ring 56 is sandwiched between the wall portion 43 surrounding the discharge port 42 of the electric oil pump 4 and the gasket 55 .

[0065] The opening 55a of the gasket 55 has an opening diameter D3 smaller than the opening diameter D1 of the opening portion 51a and larger than the opening diameter Dx of the discharge port 42 of the electric oil pump 4. The opening 56a of the seal ring 56 has an opening diameter larger than the opening diameter Dx of the discharge port 42.

[0066] The discharge port 42 of the electric oil pump 4, the opening 56a of the seal ring 56, and the opening 55a of the gasket 55 are concentrically arranged on an extension of the opening 51a (on the axis X3). This arrangement ensures that the oil OL discharged from the electric oil pump 4 is not obstructed by the gasket 55 or the seal ring 56 as it moves into the oil passage 24.

[0067] In the oil passage 24 , a check valve 93 is provided on the opposite side of the gasket 55 across the opening 51 a .

[0068] The check valve 93 may be a so-called flapper valve. The check valve 93 includes a valve body 94 and a spring Sp. The valve body 94 is provided so as to be movable forward and backward along the axis X3. The spring Sp urges the valve body 94 toward the opening 51a in the axis X3 direction.

[0069] The valve body 94 can be made of, for example, aluminum. The valve body 94 comprises a disc-shaped valve portion 95 and a cylindrical shaft portion 96. The valve portion 95 and the shaft portion 96 can be integrally formed. The valve portion 95 is positioned such that one end surface 95a of the valve portion 95 in the direction of the axis X3 faces the opening 51a. The shaft portion 96 is positioned on the other end surface 95b of the valve portion 95 in the direction of the axis X3.

[0070] The wall portion 51 is provided with a housing 513 for the check valve 93 at a position facing the opening 51a. The housing 513 is connected to the oil passage 24 in the opening direction of the opening 51a (the axis X3 direction). The housing 513 houses the check valve 93.

[0071] The housing portion 513 is a space having an inner diameter slightly larger than the outer diameter D4 of the valve portion 95 of the valve body 94. A support portion 53 for the valve body 94 is provided at the center of the bottom portion 513a of the housing portion 513. The support portion 53 is formed to protrude from the bottom portion 513a toward the oil passage 24 (electric oil pump 4).

[0072] The support portion 53 has a hole 530. The shaft 96 of the check valve 93 is inserted into the hole 530. The hole 530 is provided to open toward the oil passage 24. The hole 530 extends linearly in the support portion 53 along the axis X3 in a direction away from the oil passage 24.

[0073] The hole 530 extends beyond the support portion 53 and into the wall portion 51. An open end 530a is formed at one end of the hole 530 in the axis X3 direction. An open end 530b is formed at the other end of the hole 530 in the axis X3 direction. The open end 530a opens into the housing portion 513.

[0074] The hole 530 serves as the oil passage 77 (see Figure 1 ) and the communicating hole communicating with the oil passage 24 functions.

[0075] like Figure 3 As shown, the control valve body 7 is formed with a cylindrical wall portion 79 extending parallel to the cylindrical wall portion 78 at a distance therefrom. The cylindrical wall portion 79 surrounds the oil passage 77 branching from the line pressure oil passage 71. A cylindrical front end portion 512 extending from the wall portion 51 is fitted into the outer periphery of the front end of the cylindrical wall portion 79. The oil passage 77 extends from the interior of the control valve body 7 to the interior of the wall portion 51 via the cylindrical wall portion 79 and the front end portion 512.

[0076] like Figure 4 As shown, the opening end 530b of the hole portion 530 opens to the oil passage 77. As described above, the main pressure oil passage 71 (see Figure 1 ) branches off from the oil passage 77 and has a main pressure (hollow arrow in the figure) that serves as the initial pressure.

[0077] The shaft portion 96 of the check valve 93 is inserted into the hole portion 530 from the open end 530a. The shaft portion 96 is slidable in the hole portion 530 along the axis X3 direction.

[0078] The portion of the support portion 53 surrounding the open end 530a of the hole 530 serves as the valve seat 531. The valve seat 531 is a flat surface perpendicular to the axis X3. When the shaft portion 96 moves toward the oil passage 77 in the direction of the axis X3, a step 951 formed in the center of the valve portion 95 abuts the valve seat 531. The length of the hole 530 in the direction of the axis X3 is set to be shorter than the length of the shaft portion 96 in the direction of the axis X3. When the step 951 abuts the valve seat 531, the front end 96b of the shaft portion 96 is exposed from the hole 530 into the oil passage 77.

[0079] A spring Sp is inserted and mounted on the outer periphery of the support portion 53. One end of the spring Sp contacts the bottom 513a of the housing portion 513. The other end of the spring Sp contacts the other end surface 95b of the valve portion 95.

[0080] like Figure 4 As shown by the double-dashed line, with the valve portion 95 of the check valve 93 in contact with the end face 55b of the gasket 55, the spring Sp is installed so as to be compressed in the direction of the axis X3. That is, the spring Sp urges the valve portion 95 toward closing the opening 51a. Furthermore, oil OL flows from the oil passage 77 through the open end 530b into the hole 530. The flowing oil OL passes between the hole 530 and the shaft 96 and reaches the valve portion 95. As described above, the oil OL flowing into the oil passage 77 has a main pressure. That is, in addition to the force of the spring Sp, the main pressure acts as an auxiliary pressure on the valve portion 95, closing the opening 51a (to the left in the figure). Therefore, when the electric oil pump 4 is stopped, the valve portion 95 is pressed against the end face 55b of the gasket 55 by the force of the spring Sp and the main pressure, maintaining the valve portion 95 in a position that closes the opening 51a.

[0081] When the electric oil pump 4 is in operation, Figure 4 As shown, the oil pressure (black arrow in the figure) of the oil OL discharged from the electric oil pump 4 acts on the valve portion 95 in the direction of opening the opening 51a. When this oil pressure is greater than the force acting on the valve portion 95, that is, the force of the spring Sp and the force generated by the oil pressure supplied to the oil passage 77, the valve portion 95 compresses the spring Sp in the direction of the axis X3 and simultaneously performs a stroke in the direction away from the spacer 55.

[0082] As a result, the valve portion 95 is pressed into the oil passage 24 to a position where the step portion 951 on the other end surface 95 b side contacts the valve seat portion 531 , thereby opening the opening 51 a closed by the valve portion 95 .

[0083] When the opening 51a is opened, the discharge port 42 of the electric oil pump 4 is connected to the oil passage 24 in the wall portion 51. The oil OL discharged from the electric oil pump 4 is supplied to the oil passage 24 of the control valve body 7 through the end portion 24a.

[0084] In this manner, the check valve 93 provided in the oil passage 24 switches between connection and disconnection between the oil passage 24 and the discharge port 42 of the electric oil pump 4 in accordance with the operation and stop of the electric oil pump 4 .

[0085] Figure 5 22 is a diagram illustrating a specific structure of the check valve 91 provided in the oil passage 22. As described above, the oil passage 22 is an oil passage connecting the suction port 41 side of the electric oil pump 4 and the filter 8 (see Figure 1 ).

[0086] like Figure 5 As shown, the oil passage 22 is formed inside the control valve body 7. The check valve 91 is provided at an upstream end 22a of the oil passage 22 connected to the connection port 83 of the filter 8 in the oil feeding direction (hereinafter referred to as "end 22a").

[0087] An opening 22b is provided at the end 22a. The opening 22b is formed in a partition disposed inside the control valve body 7. Although not shown, the connection port 83 of the filter 8 is embedded in the control valve body 7 and connected to the oil passage 22 via an oil passage not shown.

[0088] The opening 22b is located in the direction of the vertical line VL relative to the connection port 83 (see Figure 2 ) above. The oil OL is sucked by the electric oil pump 4 in the direction of the vertical line VL (refer to Figure 1 ) flows from bottom to top, passes through the connecting port 83 and the opening 22b, and is introduced into the interior of the oil passage 22.

[0089] The check valve 91 may be a flapper valve having the same structure as the check valve 93. The check valve 91 includes a valve body 94 composed of a valve portion 95 and a shaft portion 96. The shaft portion 96 is slidably supported on the hole portion 22c. The hole portion 22c is formed inside the control valve body 7 in which the oil circuit 22 is formed. The hole portion 22c is arranged along the axis X direction which is the opening direction of the opening portion 22b. A support portion 22d is formed on the outer periphery of the hole portion 22c. A spring Sp is externally inserted into the support portion 22d. The spring Sp applies force to the valve portion 95. In addition, unlike the check valve 93, the check valve 91 is not connected to the oil circuit 77 (refer to Figure 1 Therefore, only the urging force of the spring Sp acts on the valve portion 95 of the check valve 91.

[0090] like Figure 5As shown, while the electric oil pump 4 is stopped, the force of the spring Sp causes the valve portion 95 to press against the opening 22b. The valve portion 95 closes the opening 22b. When the electric oil pump 4 is operating, it draws in oil OL, generating negative pressure. This negative pressure acts on the valve body 94. When this negative pressure exceeds the force of the spring Sp, the valve portion 95 of the check valve 91 displaces away from the opening 22b. This displacement of the valve portion 95 opens the opening 22b.

[0091] In this manner, the check valve 91 opens and closes the opening 22b according to the operation and stop of the electric oil pump 4. This switches the connection and disconnection between the oil passage 22 and the connection port 83 of the filter 8.

[0092] Figure 1 The check valve 92 shown in the oil passage 23 may also be a flapper valve having the same structure as the check valves 91 and 93. The oil passage 23 is connected to the discharge port 32 of the mechanical oil pump 3. Although detailed description is omitted, the check valve 92 switches between connecting and disconnecting the oil passage 23 and the discharge port 32 of the mechanical oil pump 3 in response to the operation and deactivation of the mechanical oil pump 3.

[0093] Here, if Figure 1 As shown, a high oil pressure, which serves as the initial pressure of the line pressure, is applied to the check valves 92 and 93 provided on the discharge ports 32 and 42 of the mechanical oil pump 3 and the electric oil pump 4. Therefore, the check valves 92 and 93 require pressure resistance. To improve pressure resistance, the check valves 92 and 93 may have a valve body 94 made of, for example, aluminum.

[0094] On the other hand, when electric oil pump 4 is operating, a negative pressure weaker than the initial pressure is applied to check valve 91, which is provided on the suction port 41 side of electric oil pump 4. Therefore, the pressure resistance required of check valve 91 is lower than that of check valves 92 and 93. Valve body 94 of check valve 91 can be made of, for example, resin.

[0095] Next, the operations of the check valves 91 and 93 when the electric oil pump 4 in the hydraulic pressure supply device 2 is in operation and when it is stopped will be described.

[0096] Figure 6 These are diagrams for explaining the operation of the check valves 91 and 93 when the electric oil pump 4 is in operation.

[0097] Figure 6 The figure shows the case where the electric oil pump 4 and the mechanical oil pump 3 are used together. Figure 6 The structure of the check valves 91 and 93 and the structure of the pressure regulating circuit 70 are simplified and shown in the figure.

[0098] The electric oil pump 4 is operated in conjunction with the mechanical oil pump 3 when a high oil pressure is required, for example, during downshifting of the belt-type continuously variable transmission 1 .

[0099] The electric oil pump 4 is driven by the control unit CU. When the electric oil pump 4 starts to suck the oil OL, Figure 6 As shown, the check valve 91 in the oil passage 22 is displaced toward the opening 22b due to negative pressure. When the opening 22b is opened, the oil passage 22 is connected to the connection port 83 of the filter 8. The oil OL in the oil reservoir PL is drawn into the filter 8 and filtered. The oil OL flows through the connection port 83 in the oil passage 22 and is drawn into the electric oil pump 4.

[0100] The electric oil pump 4 discharges the sucked oil OL from the discharge port 42. The check valve 93 in the oil passage 24 is displaced in the direction of opening the opening 51a by the oil pressure (discharge pressure). When the opening 51a is opened, the oil passage 24 is connected to the discharge port 42 of the electric oil pump 4. The oil OL flows through the oil passage 24. The oil pressure generated by the suction of the electric oil pump 4 is supplied to the pressure regulating circuit 70 via the oil passage 24 as the initial pressure of the line pressure.

[0101] The initial pressure supplied by the electric oil pump 4 is regulated in the pressure regulating circuit 70 along with the initial pressure supplied by the mechanical oil pump 3. The regulated oil pressure is then supplied to the oil chambers R1 and R2. When the required oil pressure is supplied to the oil chambers R1 and R2, the control unit CU stops the electric oil pump 4.

[0102] Figure 7 4 is a diagram illustrating the operation of the check valves 91 and 93 when the electric oil pump 4 is stopped. Figure 7 Illustrations of structures that are not necessary for explanation are omitted as appropriate.

[0103] like Figure 7 As shown, when the electric oil pump 4 is stopped, oil pressure (discharge pressure) no longer acts on the check valve 93 in the oil passage 24. On the other hand, the check valve 93 is acted upon by the force F1 of the spring Sp and the force F3 generated by the line pressure of the oil OL flowing into the oil passage 77. Consequently, the check valve 93 is displaced toward closing the opening 51a. When the opening 51a is closed, the connection between the oil passage 24 and the discharge port 42 of the electric oil pump 4 is severed.

[0104] Likewise, the negative pressure from the electric oil pump 4 does not act on the check valve 91 in the oil passage 22. The check valve 91 is displaced toward the closing direction of the opening 22b by the force F2 of the spring Sp. When the opening 22b is closed, the connection between the oil passage 22 and the connection port 83 of the filter 8 is severed.

[0105] Thus, when the electric oil pump 4 stops, the upstream (discharge side) and downstream (suction side) of the electric oil pump 4 are blocked by the check valves 91 and 93, respectively. Even when the electric oil pump 4 stops, the mechanical oil pump 3 continues to discharge oil OL. The provision of the check valves 91 and 93 prevents the oil OL from flowing back from the mechanical oil pump 3 or the pressure regulating circuit 70 toward the electric oil pump 4 when the electric oil pump 4 stops. This prevents a decrease in the amount of oil OL supplied from the mechanical oil pump 3 to the pressure regulating circuit 70.

[0106] Here, when the electric oil pump 4 stops and does not apply discharge pressure, the check valves 91 and 93 begin to displace in the direction of closing the oil passages 22 and 24. In the hydraulic supply device 2, the check valve 93 is controlled to close the oil passage 24 earlier than the check valve 91 closes the oil passage 22.

[0107] This is to reduce the high pressure applied to the check valve 91 of the oil passage 22 by the reverse-flowing oil OL.

[0108] If the oil passage 24 of the check valve 93 is closed later than the oil passage 22 of the check valve 91 , there is a possibility that the reverse-flowing oil OL is applied to the check valve 91 .

[0109] On the other hand, as described above, the check valve 91 of the oil passage 22 is normally actuated by the negative pressure generated by the suction of the electric oil pump 4. Since the check valve 91 is not required to have the same pressure resistance as the check valve 93, a valve body 94 made of resin may be used.

[0110] However, if the backflow of the oil OL applies high pressure to the resin valve body 94, the product life of the check valve 91 may be shortened. In order to improve the pressure resistance of the check valve 91, it is also possible to consider using, for example, an aluminum valve body 94, but this may increase the manufacturing cost of the check valve 91.

[0111] Therefore, in the hydraulic supply device 2, the check valve 93 closes the oil passage 24 earlier than the check valve 91 closes the oil passage 22. This reduces the high pressure applied to the check valve 91. For example, the stroke speed of the check valve 93 can be set faster than the stroke speed of the check valve 91. As described above, the check valve 93 is subjected to the force F3 of the line pressure in addition to the force F1 of the spring Sp, while the check valve 91 is subjected only to the force F2 of the spring Sp. In other words, the application of the force F2 of the line pressure makes it easier to set the stroke speed of the check valve 93 faster than the stroke speed of the check valve 91.

[0112] Here, the check valve 93 is not limited to applying the force F3 of the line pressure. It is also possible to set the stroke speed of the check valve 93 to be faster than the stroke speed of the check valve 91 by simply adjusting the load of the spring Sp provided on the check valves 91 and 93 respectively.

[0113] Figure 8 It is a diagram showing a comparative example.

[0114] like Figure 8 As shown, in the comparative example, no oil passage 77 is provided for inputting the line pressure to the check valve 93. The hole 630 of the shaft portion 96 supporting the check valve 93 has an open end 630a formed at one end side in the axis X3 direction and is closed at the other end side to form a bottom 630b.

[0115] When the electric oil pump 4 is in operation, the oil pressure (discharge pressure) discharged by the electric oil pump 4 is applied to the valve portion 95 of the valve body 94, similarly to the embodiment. When this oil pressure exceeds the force of the spring Sp, as indicated by the hollow arrow, the shaft portion 96 slides toward the bottom 630b of the hole portion 630, opening the opening portion 51a. At this time, the oil OL that has entered the hole portion 630 is forced out from the open end 630a of the hole portion 630 due to the sliding of the shaft portion 96. The shaft portion 96 slides further, and the valve portion 95 abuts against the valve seat portion 531. The open end 630a is closed by the valve portion 95. The inside of the hole portion 630 is sealed, reaching a state close to vacuum.

[0116] In the hole 630, which is in a near-vacuum state, negative pressure is generated, pulling the shaft 96 toward the bottom 630b. When the electric oil pump 4 is stopped, the oil pressure acting on the valve 95 is released. The force of the spring Sp causes the valve body 94 to move toward the opening 51a, closing the opening 51a.

[0117] However, when the hole 630 is in a vacuum state, negative pressure acts in a direction opposite to the force of the spring Sp. This negative pressure may slow the movement of the valve body 94. In other words, even if the load of the spring Sp is adjusted, the negative pressure will slow the stroke speed of the check valve 93. If the stroke speed of the check valve 93 slows, it may not be able to close faster than the check valve 91.

[0118] Thus, in an embodiment, if Figure 4 As shown, an oil passage 77 is provided, branching from the main pressure oil passage 71. Oil passage 77 communicates with the hole 530 via an open end 530b. Oil OL flows from oil passage 77 into the hole 530. Thus, even if the oil OL is forced out of the open end 530a due to sliding of the shaft 96, the hole 530 is unlikely to become evacuated.

[0119] Furthermore, when the electric oil pump 4 stops, the main pressure of the oil OL discharged by the mechanical oil pump 3 is also input to the hole portion 530. Figure 7 As shown, in addition to the force F1 of the spring Sp, the force F3 of the high-pressure line pressure (auxiliary pressure) also acts on the check valve 93 in the direction of closing the opening 51a of the oil passage 24. This makes it easy to set the stroke speed of the check valve 93 faster than that of the check valve 91.

[0120] As a result, the operability of the check valve 93 when closing the oil passage 24 is improved. The check valve 93 can close the oil passage 24 earlier than the check valve 91 can close the oil passage 22. This can reduce the risk of some of the oil OL in the oil passage 24 flowing back into the oil passage 22 and exerting high pressure on the check valve 91. Therefore, even when a valve body 94 made of, for example, resin is used in the check valve 91, the possibility of shortening the product life can be reduced.

[0121] Hereinafter, an example of the hydraulic pressure supply device 2 according to one embodiment of the present invention will be given.

[0122] (1) The hydraulic supply device 2 includes the line pressure oil passage 71 (supply passage) for supplying the hydraulic oil to the belt-type continuously variable transmission 1 (hydraulic working machine).

[0123] The hydraulic supply device 2 includes a mechanical oil pump 3 (first oil pump) and an electric oil pump 4 (second oil pump). The mechanical oil pump 3 supplies oil OL drawn from an oil reservoir PL (oil source) to a line pressure oil passage 71 .

[0124] The electric oil pump 4 is driven together with the mechanical oil pump 3 . Alternatively, the electric oil pump 4 is driven when the mechanical oil pump 3 is stopped. The electric oil pump 4 supplies the oil OL sucked from the oil reservoir PL to the line pressure oil passage 71 .

[0125] The hydraulic pressure supply device 2 includes a check valve 91 (first check valve) and a check valve 93 (second check valve). The check valve 91 is provided in the oil passage 22 (first oil passage) connecting the suction port 41 (suction side) of the electric oil pump 4 and the oil reservoir PL. The check valve 91 closes the oil passage 22 when the electric oil pump 4 is stopped.

[0126] The check valve 93 is provided on the oil passage 24 (second oil passage) connecting the discharge port 42 side (discharge side) of the electric oil pump 4 and the line pressure oil passage 71. The check valve 93 closes the oil passage 24 when the electric oil pump 4 stops.

[0127] The hydraulic supply device 2 includes an oil passage 77 (third oil passage). The oil passage 77 is connected to the line pressure oil passage 71. The oil OL supplied to the line pressure oil passage 71 flows into the oil passage 77.

[0128] The hydraulic supply device 2 utilizes the oil OL supplied from the mechanical oil pump 3 and flowing into the oil passage 77 as assist pressure for operating the check valve 93 when closing the oil passage 24 .

[0129] When the electric oil pump 4 stops, the hydraulic pressure supply device 2 closes the oil passage 22 on the suction port 41 side of the electric oil pump 4 using the check valve 91. The hydraulic pressure supply device 2 closes the oil passage 24 on the discharge port 42 side using the check valve 93. This prevents backflow of oil OL from the line pressure oil passage 71. Because the check valve 91 on the suction port 41 side of the electric oil pump 4 does not require the same pressure resistance as the check valve 93 on the discharge port 42 side, an inexpensive material such as resin may be used.

[0130] However, if the operation of the check valve 93 is delayed, the oil OL may flow back into the oil passage 24. When the oil OL flows back into the oil passage 24, high oil pressure acts on the check valve 91 that closes the oil passage 24. In this case, it is difficult to use an inexpensive material such as resin for the check valve 91.

[0131] The hydraulic supply device 2 includes an oil circuit 77 connected to the main pressure oil circuit 71. When the electric oil pump 4 stops, the oil OL supplied by the mechanical oil pump 3 flows from the main pressure oil circuit 71 into the oil circuit 77. The hydraulic supply device 2 uses the oil OL flowing into the oil circuit 77 as auxiliary pressure for the operation of the check valve 93. This improves the operability of the check valve 93. The hydraulic supply device 2 can quickly operate the check valve 93 and close the oil circuit 24 when the electric oil pump 4 stops. The hydraulic supply device 2 can reduce the backflow of oil OL to the oil circuit 24. As a result, the hydraulic supply device 2 can include a check valve 91 using an inexpensive raw material such as resin. The hydraulic supply device 2 can reduce manufacturing costs.

[0132] (2) In the hydraulic supply device 2, an oil passage 77 (third oil passage) is provided, for example, to branch from the line pressure oil passage 71 (supply passage). A line pressure, which serves as the initial pressure of the operating oil supplied to the belt-type continuously variable transmission 1 (hydraulic working mechanism), is input to the line pressure oil passage 71 via the mechanical oil pump 3 (first oil pump) and the electric oil pump 4 (second oil pump).

[0133] In the hydraulic supply device 2, an oil passage 77 is provided so as to branch from the line pressure oil passage 71. The line pressure, which becomes the initial pressure, is introduced into the oil passage 77. By applying a high pressure to the check valve 93, the hydraulic supply device 2 can close the check valve 93 earlier than the check valve 91.

[0134] (3) In the hydraulic supply device 2 , the check valve 93 (second check valve) includes, for example, the valve body 94 .

[0135] The valve body 94 is provided so as to be movable forward and backward along the opening direction of the discharge port 42 of the electric oil pump 4 (second oil pump), that is, in the direction of the axis X3 .

[0136] The valve body 94 includes, for example, a shaft portion 96 and a valve portion 95 .

[0137] The shaft portion 96 extends in the direction of the axis X3 (opening direction).

[0138] The valve portion 95 is provided at one end of the shaft portion 96 on the discharge port 42 side. The valve portion 95 has an outer diameter D4 that can close the discharge port 42.

[0139] The shaft portion 96 is preferably supported slidably in the direction of the axis X3 by a hole portion 530 (communication hole) that communicates the oil passage 24 (second oil passage) and the oil passage 77 (third oil passage).

[0140] The oil OL flowing into the oil passage 77 flows into the hole portion 530 , and an assist pressure acts on the valve portion 95 .

[0141] By using a flapper valve as the check valve 93 , the flow rate of the oil OL can be increased when the oil passage 24 is opened, compared with, for example, a ball valve.

[0142] Here, the check valve 93 is provided in the closed hole portion 630 (see Figure 8 In the case of the comparative example (see FIG. 2 ), when the oil passage 24 is open, the sliding of the shaft portion 96 may cause the oil OL to leak from the hole portion 630. This leakage of oil OL creates a vacuum in the hole portion 630, generating a negative pressure. This negative pressure may delay the closing of the oil passage 24 by the check valve 93 when the electric oil pump 4 stops.

[0143] The hydraulic supply device 2 is provided with a hole 530 communicating with the oil passage 77. The shaft 96 of the check valve 93 is supported by the hole 530. This prevents the shaft 96 from sliding in the hole 530, thus minimizing the generation of negative pressure. Furthermore, oil OL flows from the oil passage 77 into the hole 530, causing the main pressure, serving as the auxiliary pressure, to act on the shaft 96 supported by the hole 530. This allows the check valve 93 to rapidly operate, closing the oil passage 24.

[0144] (4) In the hydraulic supply device 2, when the electric oil pump 4 (second oil pump) is stopped, the check valve 93 (second check valve) closes the oil passage 24 earlier than the check valve 91 (first check valve) closes the oil passage 22 (first oil passage).

[0145] The check valve 91 may be made of, for example, resin, and the check valve 93 may be made of, for example, aluminum.

[0146] In the hydraulic pressure supply device 2, the oil passage 24 is closed earlier than the oil passage 22, thereby reducing the application of high oil pressure to the check valve 91. Thus, the check valve 91 can be made of, for example, inexpensive resin, and manufacturing costs can be reduced.

[0147] (5) In the hydraulic pressure supply device 2 , the electric oil pump 4 (second oil pump) draws in the oil OL from the oil reservoir PL as an oil source via the filter 8 .

[0148] The filter 8 has a connection port 83 connected to the oil passage 22 (first oil passage).

[0149] The check valve 91 blocks the connection between the oil passage 22 and the connection port 83 when the electric oil pump 4 (second oil pump) stops.

[0150] When high oil pressure is applied to the check valve 91, the oil pressure is also transmitted to the connection port 83 of the filter 8. Applying oil pressure to the connection port 83 may shorten the life of the filter 8. The oil pressure supply device 2, by providing the check valve 91, can reduce the transmission of oil pressure to the connection port 83.

[0151] (6) The hydraulic working machine may be, for example, a belt-type continuously variable transmission 1 (a transmission for a vehicle). In the hydraulic supply device 2, the mechanical oil pump 3 (first oil pump) is driven, for example, by the driving force of the engine. The electric oil pump 4 (second oil pump) is driven, for example, by the driving force of an electric motor.

[0152] The oil passage 22 connects the oil reservoir PL to the electric oil pump 4. When the electric oil pump 4 is stopped, air enters the oil passage 22 through gaps between components. This air entry causes the oil OL to leak from the oil passage 22. If the electric oil pump 4 is activated again while the oil OL is leaking from the oil passage 22, the electric oil pump 4 idles until the air is expelled from the oil passage 22. This may cause the electric oil pump 4 to delay the discharge of the oil OL.

[0153] When the electric oil pump 4 is used while the mechanical oil pump 3 is stopped, such as during an idling stop, a slight operational delay is not a problem. On the other hand, when a high oil pressure is required, such as during a downshift of the continuously variable transmission, the electric oil pump 4 is used to assist the mechanical oil pump 3. In this case, the electric oil pump 4 is required to have rapid operational responsiveness.

[0154] The hydraulic supply device 2 is provided with oil passages 22 and 24 connected to the suction port 41 and discharge port 42 of the electric oil pump 4, respectively. The hydraulic supply device 2 is also provided with check valves 91 and 93 that close the oil passages 22 and 24 when the electric oil pump 4 is stopped. This reduces leakage of oil OL from the oil passage 22 when the electric oil pump 4 is stopped, thereby improving the responsiveness of the electric oil pump 4.

[0155] As one embodiment of the present invention, Figure 2 As shown, the example of an inclined configuration of the transmission case 5 has been described. The present invention is not limited to this configuration. For example, if layout flexibility is permitted, the transmission case 5, oil pan 6, and filter 8 may be arranged horizontally without being tilted. The suction port 41 of the electric oil pump 4 may also be located in the liquid of the oil reservoir PL.

[0156] As one embodiment of the present invention, Figure 3 and Figure 4, the check valve 93 is arranged inside the transmission case 5. The present invention is not limited to this embodiment. The check valve 93 may be arranged inside the control valve body 7, similarly to the check valve 91.

[0157] As one embodiment of the present invention, an example in which the hydraulic pressure supply device is installed in a vehicle has been described. However, the present invention is not limited to this embodiment. The hydraulic pressure supply device can also be applied to devices other than vehicles.

[0158] While the embodiment of the present invention has been described above, the above embodiment merely shows one application example of the present invention and does not limit the technical scope of the present invention to the specific configuration of the above embodiment.

[0159] Explanation of symbols

[0160] 1: Belt-type continuously variable transmission (hydraulic working machinery)

[0161] 2: Hydraulic supply device

[0162] 22: Oil circuit (first oil circuit)

[0163] 24: Oil circuit (second oil circuit)

[0164] 3: Mechanical oil pump (first oil pump)

[0165] 4: Electric oil pump (second oil pump)

[0166] 41: Suction port (suction side)

[0167] 42: discharge port (discharge side)

[0168] 530: Hole (communication hole)

[0169] 71: Main pressure oil circuit (supply circuit)

[0170] 77: Oil circuit (third oil circuit)

[0171] 8: Filter

[0172] 83: Connector

[0173] 91: Check valve (first check valve)

[0174] 93: Check valve (second check valve)

[0175] 94: Valve body

[0176] 95: Valve part

[0177] 96: Shaft

[0178] OL: Oil

[0179] PL: Oil reservoir (oil source)

Claims

1. A hydraulic supply device having a supply path for supplying working oil to a hydraulic working machine, wherein: The oil pressure supply device comprises: a first oil pump that supplies oil sucked from an oil source to the supply passage; a second oil pump that is driven together with the first oil pump or when the first oil pump is stopped, and supplies oil sucked from the oil source to the supply passage; a first check valve provided in a first oil passage connecting the suction side of the second oil pump and the oil source, and closing the first oil passage when the second oil pump stops; a second check valve provided in a second oil passage connecting the discharge side of the second oil pump and the supply passage, and closing the second oil passage when the second oil pump stops; a third oil passage connected to the supply passage, into which the oil supplied to the supply passage flows; The oil supplied from the first oil pump and flowing into the third oil passage is used as assist pressure for operating the second check valve when closing the second oil passage.

2. The oil pressure supply device according to claim 1, wherein: The third oil passage is branched from the supply passage. A line pressure serving as an initial pressure of the hydraulic oil supplied to the hydraulic working machine is input to the supply passage by the first oil pump and the second oil pump.

3. The oil pressure supply device according to claim 1, wherein: The second check valve has a valve body that is arranged to be movable forward and backward in the opening direction of the discharge port of the second oil pump. The valve body comprises: a shaft portion extending along the opening direction; a valve portion provided at one end of the shaft portion on the discharge port side and having an outer diameter capable of closing the discharge port, The shaft portion is supported by a communication hole that connects the second oil passage and the third oil passage so as to be slidable in the opening direction. The oil flowing into the third oil passage flows into the communication hole, and the assist pressure acts on the valve portion.

4. The oil pressure supply device according to claim 1, wherein: When the second oil pump is stopped, the second check valve closes the second oil passage earlier than the first check valve closes the first oil passage. The first check valve is made of resin, and the second check valve is made of aluminum.

5. The oil pressure supply device according to claim 1, wherein: The second oil pump draws oil from the oil reservoir serving as the oil source through a filter. The filter has a connection port connected to the first oil passage. When the second oil pump is stopped, the first check valve disconnects the first oil passage from the connection port.

6. The hydraulic pressure supply device according to any one of claims 1 to 5, wherein: The hydraulic working machine is a transmission for a vehicle, the first oil pump is driven by the driving force of an engine, and the second oil pump is driven by the driving force of an electric motor.

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