JPH051058U - Torque converter - Google Patents

Abstract

(57) [Summary] [Purpose] The torque converter currently in use has been changed to a starter clutch type so that it can be used as a reducer brake function. In a torque converter 1 having a lock-up clutch 2 and a disc type starter clutch 3, a lock circuit operated by pilot pressure of a first solenoid valve is provided in a circuit 4 for switching both clutches 2 and 3 between ON and OFF. An up-clutch switching valve 6 and a starter clutch switching valve 8 which operates by the pilot pressure of the second solenoid valve 7 are provided respectively, and the lock-up clutch switching valve 6 and the starter clutch switching valve 8 are provided.
Is connected in series, and the first and second solenoid valves 5 and 6 are connected in parallel so that they are operated by the hydraulic pressure of the same pump 9. [Effect] It becomes possible to absorb 30-40% of energy by using the torque converter as a retarder when going downhill.
The braking ability can be greatly increased.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a torque converter used for a tire type construction machine such as a dump truck, a wheel loader, a motor grader, a truck, or the like.

[0002]

[Prior Art]

 Even for tire-type vehicles such as construction machinery, when the vehicle weight is heavy, the braking capability is limited only by the engine brake when the vehicle is descending a slope. Therefore, a wet multi-disc brake, exhaust brake, and other reducer functions are available. Are being added. A three-element one-stage two-phase or three-phase torque converter with lockup is attached between the engine and the transmission, but the starter is generally equipped with a one-way clutch.

[0003]

[Problems to be solved by the device]

 In such a vehicle, when the vehicle is descending a slope, the pump and the turbine are directly connected by engaging the lock-up clutch mounted on the torque converter in order to make the engine brake effective. Then, the speed ratio of the pump and the turbine becomes 1, so the stator spins idle and rotates in the same direction as the pump and the turbine. As a result, the torque converter has an efficiency of about 98% with almost no fluid loss and cannot function as a retarder. Therefore, the wet type multi-disc disc brake provided on the rear wheel side is utilized, but since this slides the disc to brake, it is easily damaged such as seizure. As countermeasures, cooling oil is forcedly lubricated and the number of disks is increased, but it is very expensive. In addition, the exhaust brake alone is insufficient in terms of performance, and therefore it has been desired to further improve braking performance, reduce total cost, and improve reliability.

In view of this, the present invention provides a torque converter that is used as a reducer brake function by changing the currently used torque converter to a starter clutch type. This was done with the aim of eliminating the drawbacks it has.

[0005]

[Means for Solving the Problems]

 As a means for achieving the above object, the present invention is a torque converter having a lock-up clutch and a disk type starter clutch, and is operated by a pilot pressure of a first solenoid valve in a circuit for switching both clutches between ON and OFF. And a starter clutch switching valve that operates by the pilot pressure of the second solenoid valve. The lockup clutch switching valve and the starter clutch switching valve are connected in series to each other. The second solenoid valve is connected in parallel and is operated by the hydraulic pressure of the same pump.

[0006]

[Action]

 According to the above configuration, since the first and second solenoid valves are provided, the lockup clutch and the starter clutch can be turned on at the same time, and the retarder function can be obtained.

[0007]

【Example】

 FIG. 1 is an explanatory diagram of the structure of a torque converter according to an embodiment of the present invention, and FIG. 2 is a hydraulic circuit diagram for turning on and off the lockup clutch and the starter clutch of FIG. .

The present invention relates to a torque converter 1 having a lockup clutch 2 and a disk type starter clutch 3, and a circuit 4 for switching both clutches 2 and 3 between ON and OFF. A lock-up clutch switching valve 6 that operates by pressure and a starter clutch switching valve 8 that operates by the pilot pressure of the second solenoid valve 7 are provided, and the lock-up clutch switching valve 6 and the starter clutch switching valve 8 are The first and second solenoid valves 5 and 6 are connected in series and connected in parallel so that they are operated by the hydraulic pressure of the same pump 9.

The structure of the torque converter 1 is composed of a pump 10, a turbine 11, a stator 12, etc., as shown in the schematic view of FIG. 1, and a disk type is provided between the pump 10 and the turbine 11. The lock-up clutch 2 and the stator 12 are also provided with the disk type starter clutch 3. The power from the engine 13 on the left side of the drawing is transmitted from the pump 10 through the turbine 11 to the transmission 14 on the right side of the drawing. If the stator 12 is fixed at the time of descending or is slid by the stator clutch 3, the stator 12 and the pump 10 and the turbine 11 rotate relative to each other, resulting in fluid loss. Then, the retarder function can be fulfilled, and 30 to 40% of the energy entering the torque converter 1 can be absorbed.

As shown in FIG. 2, the lockup clutch 2 is turned on and off by switching the lockup clutch switching valve 6, and the starter clutch 3 is turned on and off by switching the starter clutch switching valve 8. It has become. The lockup clutch switching valve 6 and the starter clutch switching valve 8 each have two positions, and can be switched against the spring 15 by the pilot pressure from the first and second solenoid valves 5 and 7. ing. The first and second solenoid valves 5 and 7 have the same two positions and can be turned on by energization (not shown). When not energized, they are in the off position as shown. In the figure, 16 is a tank.

Next, the operation of the torque converter 1 will be described with reference to FIG. In the torque converter (abbreviation of torque converter) mode, if both the first and second solenoid valves 5 and 7 are OFF, the lockup clutch switching valve 6 is in the b position and the lockup clutch 2 is OFF. Then, the starter clutch 3 is turned on by the hydraulic pressure from the pump 9 depending on the b position of the starter clutch switching valve 8. In the lockup mode, when the first solenoid valve 5 is turned on, the position b is switched to the position a, so that the pilot pressure acts on the lockup clutch switching valve 6 to switch the position b to the position a. The lockup clutch 3 is turned on. However, the second solenoid valve 7 is in the b position because it is off, so the starter clutch switching valve 8 is in the b position and the starter clutch 3 is off. Further, in the retarder mode, since the second solenoid valve 7 is turned to the a position, the pilot pressure switches the starter clutch switching valve 8 to the a position, so that the starter clutch 3 is also turned on. A tabular form of this state is shown in FIG.

[0012]

[Effect of the device]

 As described above, the present invention, in a torque converter having a lock-up clutch and a disk type starter clutch, operates by a pilot pressure of a first solenoid valve in a circuit for switching both clutches between ON and OFF. A lockup clutch switching valve and a starter clutch switching valve that operates by the pilot pressure of the second solenoid valve are provided, and the lockup clutch switching valve and the starter clutch switching valve are connected in series to each other. 2 Solenoid valves are connected in parallel and are operated by the hydraulic pressure of the same pump. Therefore, it is possible to absorb 30-40% of energy by using the torque converter as a retarder when descending a slope and improve the braking ability. It can be greatly improved and the conventional Ya - Rita - this amount cost reduction from possible to reduce the capacity of the dust also becomes possible.

[Brief description of drawings]

FIG. 1 is a schematic illustration showing an embodiment of the structure of a torque converter according to the present invention.

FIG. 2 is an explanatory diagram of a hydraulic circuit for turning on and off a lockup clutch and a starter clutch of FIG.

FIG. 3 is an explanatory diagram showing ON and OFF states in each mode of FIG.

[Explanation of symbols]

 1 Torque Converter 2 Lockup Clutch 3 Starter Clutch 4 Circuit 5 1st Solenoid Valve 6 Lockup Clutch Changeover Valve 7 2nd Solenoid Valve 8 Starter Clutch Changeover Valve 9 Pump

Claims (1)

Claims for utility model registration 1. In a torque converter equipped with a lock-up clutch and a disk type starter clutch, a circuit for switching both clutches ON and OFF,
A lock-up clutch switching valve operated by pilot pressure of the first solenoid valve and a starter clutch switching valve operated by pilot pressure of the second solenoid valve are provided, and the lock-up clutch switching valve and the starter clutch switching valve are provided. Is connected in series, and the first and second solenoid valves are connected in parallel so that they are operated by the hydraulic pressure of the same pump, respectively.