Abstract: A friction apply device, from among each pair of friction apply devices that are applied to achieve a speed from first speed to fourth speed, that is to be placed in a slipping state is selected based on a heat load when a neutral control is executed. As a result, it is possible to continue to execute the neutral control without the durability of the friction apply device being impaired by the heat load, for example, thereby increasing a fuel efficiency effect and the like achieved by the neutral control.

Abstract: There is provided a hydraulic pressure control apparatus for a vehicular hydraulic power transmission device with a lock-up clutch, in which an increase in the temperature of hydraulic oil in an engagement side oil chamber is suppressed, durability of frictional material is improved, and the lock-up clutch is appropriately controlled.

Abstract: A fluid pressure control circuit includes a fluid pressure device which is operated by a fluid pressure; a control valve which is connected to the fluid pressure device via a connecting passage, and which changes a flow rate of predetermined fluid that is to be supplied to the fluid pressure device or that is to be discharged from the fluid pressure device according to a position of a valve element; and a pressure difference reflecting device which moves the valve element based on a difference in the fluid pressure between predetermined two different portions in the connecting passage and which changes the flow rate of the fluid that is to be supplied or to be discharged through the control valve according to the fluid pressure difference. With this fluid pressure control circuit, it is possible to obtain excellent responsiveness during supply/discharge of the fluid, change in the fluid pressure or the like, without increasing the amount of the fluid to be consumed.

Abstract: A pair of feedback chambers is provided in a supply/discharge switching control valve, and the hydraulic pressure is introduced from a portion on the upstream side of the orifice provided in the communication passage through the second feedback passage, and is introduced from a portion on the downstream side of the orifice provided in the communication passage through the first feedback passage. Therefore, the responsiveness is enhanced, compared with the case where only the first feedback chamber is provided. Also, the overshoot and the undershoot of the fluid pressure, and the pressure fluctuation are effectively suppressed, compared with the case where only the second feedback chamber is provided.

Abstract: In a hydraulic control apparatus, a valve accommodation hole of a valve body also serves as a sleeve, and a spool is fitted in the valve accommodation hole. Therefore, the size of the valve accommodation hole is reduced by an amount corresponding to the thickness of the sleeve, thus reducing the weight and size of the hydraulic control apparatus. Also, a solenoid portion is detachably fixed to the valve body with a snap-fastener. Accordingly, in the case of a failure of the solenoid valve, only one of the solenoid portion and the spool can be easily replaced depending upon the type of the failure by canceling fixation with the snap-fastener.