JP7612480B2 - Torque converter device - Google Patents

Description

The present invention relates to a torque converter device.

Conventionally, a work vehicle equipped with a torque converter device having a torque converter and a lock-up clutch is known (see, for example, Patent Document 1). The lock-up clutch includes a piston that is hydraulically operated and a disk that is engaged or released by the operation of the piston.

When the vehicle speed reaches or exceeds a certain speed, the piston operates to engage the disc, turning the lock-up clutch on. When the lock-up clutch is on, power from the engine is transmitted directly to the output shaft of the transmission through the lock-up clutch without passing through the torque converter.

Japanese Utility Model Application Publication No. 5-12836

Here, the lock-up clutch is located in a hydraulic circuit that supplies hydraulic oil to the torque converter, and the lock-up clutch discs are lubricated by the hydraulic oil supplied to the torque converter.

When a lock-up clutch is placed in a hydraulic circuit that supplies hydraulic oil to a torque converter, the internal pressure of the torque converter is constantly applied to the piston, so hydraulic pressure that includes the internal pressure of the torque converter is required to operate the piston.

However, because the internal pressure of the torque converter fluctuates depending on the rotation speed and oil temperature, it is difficult to appropriately hydraulically control the piston. As a result, when the lock-up clutch transitions to the on state (i.e., the disc is engaged), shocks are likely to occur due to improper clutch hydraulic control.

The objective of this disclosure is to provide a torque converter device that can suppress the occurrence of shock when the lockup clutch transitions to the on state.

The torque converter device according to the present disclosure includes a torque converter, a lock-up clutch, a first oil passage, and a second oil passage. The lock-up clutch has a piston that is hydraulically operated and a disk that is engaged or released by the operation of the piston. The first oil passage supplies hydraulic oil to the inside of the torque converter. The second oil passage supplies hydraulic oil to the disk. The second oil passage is independent of the first oil passage.

This disclosure provides a torque converter device that can prevent shocks from occurring when the lockup clutch transitions to the on state.

FIG. 1 is a side view of a work vehicle according to an embodiment. 1 is a cross-sectional view of a torque converter device according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a hydraulic circuit according to the embodiment.

An embodiment of a torque converter device according to the present disclosure will be described with reference to the drawings. The torque converter device according to the present disclosure is mounted on a work vehicle. Examples of work vehicles include, but are not limited to, wheel loaders, dump trucks, bulldozers, and forklifts.

(Work vehicle 1)
FIG. 1 is a side view of a work vehicle 1. FIG.

The work vehicle 1 according to this embodiment is a wheel loader. The work vehicle 1 includes a power source 2, a hydraulic pump 3, a torque converter device 4, a transmission 5, a traveling device 6, and a controller 7.

The power source 2 is, for example, an engine. The hydraulic pump 3 is driven by the power source 2.

The torque converter device 4 is disposed between the power source 2 and the transmission 5. The torque converter device 4 transmits the power from the power source 2 to the transmission 5.

The transmission 5 is disposed between the torque converter device 4 and the traveling device 6. The transmission 5 transmits the power from the power source 2, which is transmitted via the torque converter device 4, to the traveling device 6. The transmission 5 has multiple hydraulic clutches for switching between forward and reverse travel, multiple hydraulic clutches for switching between speed stages, a gear mechanism, etc.

The running device 6 is, for example, a tire. The controller 7 controls the power source 2, the torque converter device 4, and the transmission 5.

(Torque converter device 4)
FIG. 2 is a cross-sectional view of the torque converter device 4.

The torque converter device 4 includes a torque converter 21, a lock-up clutch 22, a first oil passage L1, a second oil passage L2, and a third oil passage L3.

The torque converter 21 includes a pump impeller P, a turbine T, and a stator S.

The lock-up clutch 22 is a hydraulically operated clutch. The lock-up clutch 22 has a piston 31, a disk 32, a biasing member 33, a lock-up housing 34, a drive case 35, a rim 36, a first rotating ring seal 37, and a second rotating ring seal 38.

The piston 31 is inserted into an oil chamber 34a formed in the lock-up housing 34. The piston 31 is movable along a direction parallel to the axis of the input shaft 2a connected to the power source 2.

The internal teeth of the disk 32 mesh (fit) with the external teeth of the rim 36. The disk 32 is disposed between the piston 31 and a friction surface 35b formed on the drive case 35.

The biasing member 33 is disposed between the piston 31 and the drive case 35. The biasing member 33 biases the piston 31 in the opposite direction to the disk 32. For example, a coil spring can be used as the biasing member 33.

The lock-up housing 34 and the drive case 35 are connected to each other. For example, bolts can be used to connect the lock-up housing 34 and the drive case 35. The drive case 35 is an example of a "first member" according to the present invention. The lock-up housing 34 is an example of a "second member" according to the present invention.

The rim 36 is fixed to the output shaft 5a connected to the transmission 5 and to the turbine T. The rim 36 rotates integrally with the output shaft 5a and the turbine T. The rim 36 is disposed between the lock-up housing 34 and the drive case 35. The rim 36 rotates relative to the lock-up housing 34 and the drive case 35. As described above, the rim 36 is provided with external teeth that mesh with the internal teeth of the disc 32. The rim 36 is an example of a "third member" according to the present invention.

The first rotating ring seal 37 is disposed between the lock-up housing 34 and the rim 36. The first rotating ring seal 37 provides a seal between the lock-up housing 34 and the rim 36.

The second rotating ring seal 38 is disposed between the drive case 35 and the rim 36. The second rotating ring seal 38 provides a seal between the drive case 35 and the rim 36.

The first oil passage L1 supplies hydraulic oil to the inside of the torque converter 21. The first oil passage L1 is formed inside the drive case 35.

The second oil passage L2 supplies hydraulic oil to the disk 32. The disk 32 is lubricated and cooled by the hydraulic oil supplied from the second oil passage L2. The second oil passage L2 is formed inside the input shaft 2a connected to the power source 2 and the lock-up housing 34.

Here, the second oil passage L2 is independent from the first oil passage L1 by the first rotating ring seal 37 and the second rotating ring seal 38. The hydraulic oil supplied from the first oil passage L1 to the inside of the torque converter 21 is discharged to the outside of the torque converter 21 without acting on the disk 32 and the piston 31. In this way, since the second oil passage L2 is independent from the first oil passage L1, the internal pressure of the torque converter 21 is not applied to the piston 31. Therefore, since it is not necessary to supply hydraulic pressure to which the internal pressure of the torque converter 21 is added in order to operate the piston 31, it is easy to control the piston 31 to an appropriate hydraulic pressure. Therefore, it is possible to suppress the occurrence of shock in the process until the lock-up clutch transitions to the ON state (i.e., the disk 32 is engaged).

In addition, hydraulic oil at a lower temperature can be supplied to the disk 32 compared to when hydraulic oil heated inside the torque converter 21 is supplied to the disk 32. This allows for a wider range of options for the construction material of the disk 32.

The third oil passage L3 supplies hydraulic oil to the piston 31. The third oil passage L3 is formed inside the output shaft 5a to the transmission 5 and inside the lock-up housing 34. The piston 31 is actuated by hydraulic oil supplied from the third oil passage L3 to the oil chamber 34a.

When the oil pressure in the oil chamber 34a increases, the piston 31 moves toward the disk 32, and the disk 32 pushed by the piston 31 presses against the friction surface 35b. This causes the lock-up clutch to turn on (i.e., the disk 32 is engaged), and the turbine T and the pump impeller P rotate in unison. As a result, the power from the power source 2 is transmitted directly to the output shaft 5a of the transmission 5 via the lock-up clutch 22 without passing through the torque converter 21.

On the other hand, when the oil pressure in the oil chamber 34a becomes low, the piston 31 moves in the opposite direction to the disk 32 due to the biasing force received from the biasing member 33, and the disk 32 moves away from the friction surface 35b. As a result, the lock-up clutch is turned off (i.e., the disk 32 is in an open state), and the power from the power source 2 is transmitted to the output shaft 5a of the transmission 5 via the torque converter 21.

The second oil passage L2 is independent of the third oil passage L3. The hydraulic oil supplied to the piston 31 from the third oil passage L3 does not act on the disk 32, and is not supplied to the inside of the torque converter 21.

(Hydraulic circuit)
FIG. 3 is a schematic diagram showing a hydraulic circuit 40 provided in the work vehicle 1.

The hydraulic circuit 40 includes oil passages L10 to L16 in addition to the first to third oil passages L1 to L3 described above.

The oil passage L10 extends from an oil pan 41 in which hydraulic oil is stored to a connection point P1. A hydraulic pump 3 connected to a power source 2 and a main relief valve 42 are arranged on the oil passage L10. The main relief valve 42 adjusts the pressure of the hydraulic oil. The oil passage L10 branches into a first oil passage L1 and an oil passage L11 at a connection point P1. The first oil passage L1 extends from the connection point P1 to the torque converter 21. The oil passage L11 extends from the connection point P1 to the connection point P2. A torque converter relief valve 43 is arranged on the oil passage L11. The torque converter relief valve 43 adjusts the pressure of the hydraulic oil so that the internal pressure of the torque converter 21 does not become too high above the steady pressure.

Oil passage L12 extends from the torque converter 21 to the connection point P2. Oil passage L11 and oil passage L12 merge at the connection point P2. Oil passage L13 extends from the connection point P2 to the connection point P3. An oil cooler 44 is disposed on the oil passage L13. The oil cooler 44 cools the hydraulic oil that has passed through the torque converter 21. Oil passage L12 branches into oil passages L14, 15 and a second oil passage L2 at the connection point P3.

The oil passage L14 extends from the connection point P3 to the planetary portion of the transmission 5. The hydraulic oil supplied from the oil passage L14 to the planetary portion of the transmission 5 is returned to the oil pan 41. The oil passage L15 extends from the connection point P3 to the transfer (not shown). The hydraulic oil supplied from the oil passage L15 to the transfer is returned to the oil pan 41. The second oil passage L2 extends from the connection point P3 to the disk 32 of the lock-up clutch 22. The hydraulic oil supplied from the second oil passage L2 to the disk 32 is returned to the oil pan 41.

Oil passage L16 branches off from oil passage L10 at connection point P4. Oil passage L16 extends from connection point P4 to each hydraulic clutch of the transmission 5. A third oil passage L3 branches off from oil passage L16 at connection point P5. The third oil passage L3 extends from connection point P5 to the piston 31 of the lock-up clutch 22. A lock-up clutch hydraulic control valve 45 is disposed on the third oil passage L3. The opening of the lock-up clutch hydraulic control valve 45 is controlled by the controller 7.

As shown in FIG. 3, the second oil passage L2 is independent of the first oil passage L1. The second oil passage L2 is not directly connected to the first oil passage L1. However, the hydraulic oil supplied to the inside of the torque converter 21 from the first oil passage L1 can flow into the second oil passage L2 via the oil passages L12 and L13. The hydraulic oil flowing into the second oil passage L2 has already been cooled by the oil cooler 44, so the cooling effect of the disk 32 of the lock-up clutch 22 can be improved.

1 Work vehicle 2 Power source 2
3 Hydraulic pump 4 Torque converter device 5 Transmission 6 Travel device 7 Controller 21 Torque converter 22 Lock-up clutch 31 Piston 32 Disk 33 Pressing member L1 First oil passage L2 Second oil passage L3 Third oil passage

Claims (4)

A torque converter;
a lock-up clutch having a hydraulically actuated piston and a disk that is engaged or disengaged by actuation of the piston;
a first oil passage for supplying hydraulic oil to an inside of the torque converter;
A second oil passage for supplying hydraulic oil to the disk;
A first member having the first oil passage formed therein;
A second member having the second oil passage formed therein;
A third member disposed between the first member and the second member; and
a first rotating ring seal disposed between the third member and the second member;
a second rotating ring seal disposed between the third member and the first member;
Equipped with
The second oil passage is independent of the first oil passage.
Torque converter device . A torque converter;
a lock-up clutch having a hydraulically actuated piston and a disk that is engaged or disengaged by actuation of the piston;
a first oil passage for supplying hydraulic oil to an inside of the torque converter;
A second oil passage for supplying hydraulic oil to the disk;
a drive case having the first oil passage formed therein;
an input shaft and a lock-up housing having the second oil passage formed therein;
a rim disposed between the drive case and the lock-up housing;
a first rotating ring seal disposed between the rim and the lock-up housing;
a second rotating ring seal disposed between the rim and the drive case;
Equipped with
The second oil passage is independent of the first oil passage.
Torque converter device . A third oil passage is provided for supplying hydraulic oil to the piston.
The second oil passage is independent of the third oil passage.
3. The torque converter device according to claim 2 . The third oil passage is formed inside the output shaft and the lock-up housing.
4. The torque converter device according to claim 3 .

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