CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority under 35 U.S.C. § 119 to Japanese Application No. 2018-227982 filed on Dec. 5, 2018, the entire contents of which are hereby incorporated herein by reference.

1. FIELD OF THE INVENTION

The present disclosure relates to a hydraulic control apparatus.

2. BACKGROUND

Hydraulic pressure supply systems in which a full discharge mode and a half discharge mode are switched are known. A constitution in which the full discharge mode and the half discharge mode are switched, for instance, using a solenoid valve is disclosed in Japanese Unexamined Patent Application, First Publication No. 2015-057559.

In the hydraulic pressure supply systems as described above, because a flow rate of discharged oil is abruptly increased when the half discharge mode is switched to the full discharge mode, a supplied hydraulic pressure is abruptly changed. It is also conceivable that, for instance, an accumulator be provided to curb this abrupt change in hydraulic pressure, but there are problems therein such as the number of components of the hydraulic pressure supply system is increased and that the hydraulic pressure supply system is increased in size.

SUMMARY

Example embodiments of the present disclosure provide hydraulic control apparatuses each capable of limiting an abrupt change in hydraulic pressure supplied to a control target while limiting an increase in the number of components and an increase in size.

An example embodiment of a hydraulic control apparatus of the present disclosure is a hydraulic control apparatus that controls a control target using a hydraulic pressure. The hydraulic control apparatus includes an oil pump assembly including a first discharge port and a second discharge port, an input-side oil passage through which oil suctioned from an oil tank to the oil pump assembly passes, a first oil passage into which oil discharged from the first discharge port flows, a second oil passage into which oil discharged from the second discharge port flows, an output-side oil passage into which the oil from the first oil passage and the oil from the second oil passage flow and which supplies a hydraulic pressure to the control target, and a pressure regulating check valve provided on the second oil passage, checking a flow of the oil from the output-side oil passage to the second discharge port, and regulating a hydraulic pressure in the second oil passage. The pressure regulating check valve includes a housing including a spool hole that extends in a predetermined direction and includes a bottom on a first side thereof in the predetermined direction, an inflow hole that is located on a second side of the spool hole in the predetermined direction and is joined with an interior of the spool hole, and an outflow hole that is provided on an inner circumferential surface of the spool hole and is joined with the interior of the spool hole, a valve that is housed in the interior of the spool hole to be movable in the predetermined direction and includes a valve body that can open/close the inflow hole, a first elastic portion that is housed in the interior of the spool hole between the valve body and the bottom in the predetermined direction, extends in the predetermined direction, and applies an elastic force toward the other side in the predetermined direction to the valve body, and a second elastic portion that is housed in the interior of the spool hole between the valve body and the bottom in the predetermined direction and extends in the predetermined direction. A natural length of the second elastic portion in the predetermined direction is shorter than a natural length of the first elastic portion in the predetermined direction, and is shorter than a distance between the valve body and the bottom in the predetermined direction when the valve body closes the inflow hole. The second elastic portion applies an elastic force toward the second side in the predetermined direction to the valve body in a state in which the valve body has opened the inflow hole.

According to example embodiments of the present disclosure, hydraulic control apparatuses are able to limit an abrupt change in a hydraulic pressure supplied to a control target while limiting an increase in the number of components and an increase in size.

The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.

