What is claimed is:
1. A cushion device for a hydraulic cylinder, comprising:
a piston slidably housed in a cylinder tube,
a cylinder head through which a piston rod connected to the piston slidably penetrates,
a cushion ring fixed to the piston rod,
a cushion seal, the cushion seal being free to move within a certain range in the axial direction of the piston rod on the side of the cylinder head, and the cushion ring penetrating the inner circumference of the cushion seal in the vicinity of the end of the piston stroke, and restricting flow of fluid from an oil chamber in the cylinder tube to exert a cushion effect, and
a spacer, the spacer being arranged on the inner side of the cushion seal in the axial direction and free to move by the same amount as the cushion seal, and its inner diameter being set larger than the inner diameter of the cushion seal.
2. The cushion device as defined in claim 1, wherein the cushion seal and spacer are arranged in the axial direction inside the holder, and arranged free to move within a certain range.
3. The cushion device as defined in claim 2, wherein a guide part smaller than the inner diameter of the stopper restricting motion of the spacer provided in the holder, is provided at the tip of the spacer.
4. The cushion device as defined in claim 3, wherein the axial length of the guide part is set larger than the tolerance displacement amount of the spacer.
5. The cushion device as defined in claim 1, further comprising:
a bypass passage whereof the effective cross-sectional surface area varies in the axial direction of the cushion seal, the bypass passage communicating with the oil chamber and allowing fluid to bypass a passage formed between the outer circumference of the cushion ring and the inner circumference of the cushion seal.
6. The cushion device as defined in claim 5, wherein the bypass passage becomes narrower when the cushion effect is produced due to the motion of the piston, and becomes larger due to its motion in the opposite direction.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A control apparatus of a hybrid electric vehicle, comprising:
a clutch provided between an engine and a motor generating power;
a transmission serially connected to the motor;
a driving information detector detecting driving information including an output speed of the motor, an output speed of the transmission, and a rotation speed of a driving shaft serially connected to the transmission; and
a controller limiting torque of the motor or speed of the motor to a predetermined level or less when a difference between the output speed of the motor and the output speed of the transmission detected by the driving information detector is higher than a predetermined value.
2. The control apparatus of claim 1,
wherein the output speed of the transmission is inversely calculated from the rotation speed of the driving shaft.
3. A control method of a hybrid electric vehicle including an engine, a clutch, a motor, a transmission, and a driving shaft sequentially connected in series, the control method comprising:
detecting an output speed of the motor and an output speed of the transmission by a driving information detector of the hybrid electric vehicle;
determining whether a difference between the output speed of the motor and the output speed of the transmission is higher than a predetermined value by a controller of the hybrid electric vehicle; and
limiting an input torque of the motor or an input speed of the motor to a predetermined level or less when the difference between the output speed of the motor and the output speed of the transmission detected by the driving information detector is higher than the predetermined value.
4. The control method of claim 3,
wherein the output speed of the transmission is inversely calculated from the rotation speed of the driving shaft by the controller.
5. A control apparatus of a hybrid electric vehicle, comprising:
a clutch provided between an engine and a motor generating power;
a transmission serially connected to the motor;
a driving information detector detecting driving information, including a shift stage of the transmission and an output speed of the motor; and
a controller limiting an input torque of the motor or an input speed of the motor under a predetermined level when a difference between a torque of the motor calculated from the shift stage detected by the driving information detector and the output torque of the motor is higher than a predetermined value.
6. A control method of a hybrid electric vehicle including an engine, a clutch, a motor, a transmission, and a driving shaft sequentially connected in series, the control method comprising:
calculating a torque of the motor corresponding to a shift stage of the transmission by a controller of the hybrid electric vehicle;
determining whether a difference between the torque of the motor calculated by the controller and an output torque of the motor is higher than a predetermined value; and
limiting an input torque of the motor to a predetermined level or less when the difference between the torque of the motor calculated by the controller and the output torque of the motor is higher than the predetermined value.