1. Field of the Invention
The present invention relates to a control valve and, more particularly, to a mixed water control valve for a faucet to control the temperature of a mixture of cold and hot water of the faucet.
2. Description of the Related Art
A faucet comprises a control valve to mix the cold water from a cold water source and the hot water from a hot water source and to inject the mixed water outwardly for use with a user. Thus, the mixed water has a proper temperature so that the user can use the water comfortably. However, when the water flow from the cold water source or the hot water source is reduced or stops accidentally due to an irregular condition, the water pressure of the cold water and the hot water is not balanced, so that the water temperature is increased or decreased to an excessive extent instantaneously to make the water too hot or cold, thereby easily causing an uncomfortable sensation to the user due to the too hot or cold water or causing danger to the user due to the too hot water (the user is easily scalded by the too hot water).
A conventional mixed water control valve for a faucet in accordance with the prior art shown in FIG. 9 comprises a valve body 40, a balance unit 50 mounted in the valve body 40, and a pressure regulating member 52 movably mounted in the balance unit 50. The valve body 40 has a lower end provided with two water inlet holes 41 and an upper end provided with two water outlet holes 43. One of the two water inlet holes 41 of the valve body 40 is connected to a cold water source (not shown) to deliver cold water, and the other one of the two water inlet holes 41 of the valve body 40 is connected to a hot water source (not shown) to deliver hot water. The balance unit 50 is provided with two connecting holes 51 each connected to a respective one of the two water outlet holes 43 of the valve body 40. The pressure regulating member 52 is provided with two regulating holes 521 each connected between a respective one of the two connecting holes 51 and a respective one of the two water inlet holes 41 of the valve body 40.
In operation, the cold or hot water from each of the two water inlet holes 41 of the valve body 40 in turn flows through a respective one of the two connecting holes 51 of the balance unit 50 and a respective one of the two regulating holes 521 of the pressure regulating member 52 into a respective one of the two water outlet holes 43 of the valve body 40. Then, the cold water and the hot water are mixed in the valve body 40 to form mixed cold and hot water. Then, the mixed water is injected outwardly from the valve body 40 for use with a user.
On the other hand, when the water flow of a first one (for example, the hot water terminal) of the two water inlet holes 41 is reduced accidentally or stopped abnormally due to an irregular condition, the water pressure of the first one (the hot water terminal) of the two water inlet holes 41 is reduced or disappears, and the greater water pressure of a second one (for example, the cold water terminal) of the two water inlet holes 41 will push the pressure regulating member 52 toward the first one (the hot water terminal) of the two water inlet holes 41, so that the pressure regulating member 52 is moved in the balance unit 50 to reduce or block the overlapping area of the respective regulating hole 521 of the pressure regulating member 52 and the respective connecting hole 51 of the balance unit 50 at the second one (the cold water terminal) of the two water inlet holes 41 so as to reduce or stop the water flow of the second one (the cold water terminal) of the two water inlet holes 41. Thus, the pressure regulating member 52 is moved by a pressure differential between the two water inlet holes 41 so that the water flow of the two water inlet holes 41 can be regulated by movement of the pressure regulating member 52 so as to achieve a water pressure balance and to stabilize the temperature of the mixed water.
However, the pressure regulating member 52 will block one of the two water outlet holes 43 of the valve body 40 during movement in the balance unit 50 to reduce the water flow in one of the two water outlet holes 43 of the valve body 40 so that the water pressure in the valve body 40 is unsteady.