Combination faucet and method of mixing hot water with cold water

A combination faucet comprising:

• a mixing valve having a movable valve member for adjusting a mixing ratio of hot water to cold water;
• a first spring comprising a material which varies a spring constant of said first spring according to a temperature variation in a predetermined temperature range, said first spring pressing said movable valve member in a predetermined first direction for reducing the ratio of said hot water to said cold water in response to an increase in a temperature of a water mixture of hot water and cold water flowing out of said mixing valve;
• a second spring for pressing said movable valve member in a predetermined second direction opposite to said predetermined first direction;
• pre-load adjustment means for adjusting a pre-load of at least one spring of said first spring and said second spring;
• temperature detection means for detecting temperature of said water mixture;
• pre-load control means feed-back controlling said pre-load adjustment means to compensate for deviation between the temperature of said water mixture detected by said temperature detection means and a target temperature;
• and
• control gain determination means for determining a feed-back control gain of said pre-load control means based on mixing conditions of hot water and cold water.

A combination faucet comprising:

• a mixing valve having a movable valve member for adjusting a mixing ratio of hot water to cold water;
• a first spring comprising a material which varies a spring constant of said first spring according to a temperature variation in a predetermined temperature range, said first spring pressing said movable valve member in a predetermined first direction for reducing the ratio of said hot water to said cold water in response to an increase in a temperature of a water mixture of hot and cold water flowing out of said mixing valve;
• a second spring for pressing said movable valve member in a predetermined second direction opposite to said predetermined first direction;
• pre-load adjustment means for adjusting a pre-load of at least one spring of said first spring and said second spring;
• temperature detection means for detecting temperature of said water mixture;
• initial pre-load setting means for controlling said pre-load adjustment means to set the pre-load equal to an initial value corresponding to a target temperature of said water mixture;
• control determination means determining whether a feedback control routine is or is not to be executed, according to magnitude of a deviation between the temperature of said water mixture detected by said temperature detection means and said target temperature after a setting of said pre-load by said initial pre-load setting means, and
• pre-load control means for controlling said pre-load adjustment means to compensate for said deviation when said control determination means determines said feedback control routine has been executed.

A combination faucet comprising:

• a mixing valve having a movable valve member for adjusting a mixing ratio of hot water to cold water;
• a first spring comprising a material which varies a spring constant of a material which varies a spring constant of said first spring according to a temperature variation in a predetermined temperature range, said first spring pressing said movable valve member in a predetermined first direction for reducing the ratio of said hot water to said cold water in response to an increase in a temperature of water mixture of hot water and cold water flowing out of said mixing valve;
• a second spring for pressing said movable valve member in a predetermined second direction opposite to said predetermined first direction;
• pre-load adjustment means for adjusting a pre-load of at least one spring of said first spring and said second spring;
• temperature detection means for detecting temperature of said water mixture;
• pre-load memory means for storing a relationship between a target temperature of said water mixture and said pre-load;
• pre-load setting means for controlling said pre-load adjustment means to set said pre-load equal to an initial value corresponding to said target temperature according to the relationship stored in said pre-load memory means;
• pre-load control means for controlling said pre-load adjustment means to compensate for deviation between the temperature of said water mixture detected by said temperature detection means and said target temperature after the setting of said pre-load by said pre-load setting means;
• and
• updating means for updating the relationship stored in said pre-load memory means with a new set of values of said target temperature and said pre-load when a predetermined condition is fulfilled by said deviation of the temperature of said water mixture detected by said temperature detection means from said target temperature.

A combination faucet comprising:

• a mixing valve having a movable valve member for adjusting a mixing ratio of hot water to cold water;
• a first spring comprising a material which varies a spring constant of said first spring according to a temperature variation in a predetermined temperature range, said first spring pressing said movable valve member in a predetermined first direction for reducing the ratio of said hot water to said cold water in response to an increase in a temperature of a water mixture of hot water and cold water flowing out of said mixing valve;
• a second spring for pressing said movable valve member in a predetermined second direction opposite to said predetermined first direction;
• pre-load adjustment means for adjusting a pre-load of at least one spring of said first spring and said second spring;
• plural pre-loads memory means for storing a plurality of relations between said pre-load and a target temperature of said water mixture;
• pre-load selection means which, based on inputs of predetermined data, selects a first relation of said plurality of relations between the pre-load and the target temperature stored in said plural pre-loads memory means;
• and
• pre-load setting means for controlling said pre-load adjustment means to set said pre-load equal to an initial value corresponding to said target temperature according to said first relation selected by said pre-load selection means.

A method of mixing hot water with cold water, said method comprising steps of:

• 1. regulating a mixing ratio of said hot water to said cold water based on a position of a movable valve member disposed in a mixing valve;
• 2. determining the position of said movable valve member by:
• (2a) pressing said movable valve member with a first spring in a predetermined first direction for reducing the mixing ratio of hot water to cold water in response to an increase in a temperature of a water mixture of hot water and cold water flowing out of said mixing valve, said first spring being composed of a material which varies a spring constant of said first spring according to a temperature variation in a predetermined temperature change;
• and
• (2b) pressing said movable valve member with a second spring in a predetermined second direction opposite to said predetermined first direction,
• said method further comprising steps of:
• 3. adjusting a pre-load of at least one spring of said first spring and said second spring to set said pre-load equal to an initial value corresponding to a target temperature of said water mixture;
• 4. detecting the temperature of said water mixture after said step 3;
• and
• 5. when the temperature of said water mixture detected in said step 4, deviates from said target temperature, adjusting the pre-load of at least one spring of said first spring and said second spring to compensate for said deviation.

A method of mixing hot water with cold water, said method comprising steps of:

• 1. regulating a mixing ratio of said hot water to said cold water based on a position of a movable valve member disposed in a mixing valve;
• 2. determining the position of said movable valve member by:
• (2a) pressing said movable valve member with a first spring in a predetermined first direction for reducing the mixing ratio of hot water to cold water in response to an increase in a temperature of a water mixture of hot water and cold water flowing out of said mixing valve, said first spring being composed of a material which varies a spring constant of said first spring according to a temperature variation in a predetermined temperature change;
• and
• (2b) pressing said movable valve member with a second spring in a predetermined second direction opposite to said predetermined first direction,
• said method further comprising steps of:
• 3. detecting the temperature of said water mixture;
• 4. when the temperature of said water mixture detected in said step 3, deviates from a target temperature, determining a gain of a feed-back control based on mixing conditions of hot water and cold water;
• and
• 5. feed-back controlling the pre-load of at least one spring of said first spring and said second spring based on said gain to compensate for said deviation.

A method of mixing hot water with cold water, said method comprising steps of:

• 1. regulating a mixing ratio of said hot water to said cold water based on a position of a movable valve member disposed in a mixing valve;
• 2. determining the position of said movable valve member by:
• (2a) pressing said movable valve member with a first spring in a predetermined first direction for reducing the mixing ratio of hot water to cold water in response to an increase in a temperature of a water mixture of hot water and cold water flowing out of said mixing valve, said first spring being composed of a material which varies a spring constant of said first spring according to a temperature variation in a predetermined temperature change;
• and
• (2b) pressing said movable valve member with a second spring in a predetermined second direction opposite to said predetermined first direction,
• said method further comprising steps of:
• 3. adjusting a pre-load of at least one spring of said first spring and said second spring to set said pre-load equal to an initial value corresponding to a target temperature of said water mixture;
• 4. detecting the temperature of said water mixture after said step 3;
• 5. when the temperature of said water mixture detected in said step 4 deviates from said target mixture, determining whether a feed-back control routine is to be executed or not based on a magnitude of said deviation;
• and
• 6. when execution of said feed-back control routine is determined in said step 5, controlling the pre-load of at least one of said first spring and said second spring to compensate for said deviation.

A method of mixing hot water with cold water, said method comprising steps of:

• 1. regulating a mixing ratio of said hot water to said cold water based on a position of a movable valve member disposed in a mixing valve;
• 2. determining the position of said movable valve member by:
• (2a) pressing said movable valve member with a first spring in a predetermined first direction for reducing the mixing ratio of hot water to cold water in response to an increase in a temperature of a water mixture of hot water and cold water flowing out of said mixing valve, said first spring being composed of a material which varies a spring constant of said first spring according to a temperature variation in a predetermined temperature change;
• and
• (2b) pressing said movable valve member with a second spring in a predetermined second direction opposite to said predetermined first direction,
• said method further comprising steps of:
• 3. storing a relationship between a target temperature of said water mixture and a pre-load;
• 4. adjusting a pre-load of at least one spring of said first spring and said second spring and setting said pre-load equal to an initial value corresponding to a target temperature of said water mixture based on the relationship stored in said step 3;
• 5. detecting the temperature of said water mixture after said step 4;
• 6. when the temperature of said water mixture detected in said step 5, deviates from said target temperature, adjusting the pre-load of at least one spring of said first spring and said second spring to compensate for said deviation;
• and
• 7. updating the relationship stored in said step 3, with a new set of values of said target temperature and said pre-load when a predetermined condition is fulfilled between said deviation of the temperature of said water mixture detected by said temperature detection means and said target temperature.

A method of mixing hot water with cold water, said method comprising steps of:

• 1. regulating a mixing ratio of said hot water to said cold water based on a position of a movable valve member disposed in a mixing valve;
• 2. determining the position of said movable valve member by:
• (2a) pressing said movable valve member with a first spring in a predetermined first direction for reducing the mixing ratio of hot water to cold water in response to an increase in a temperature of a water mixture of hot water and cold water flowing out of said mixing valve, said first spring being composed of a material which varies a spring constant of said first spring according to a temperature variation in a predetermined temperature change;
• and
• (2b) pressing said movable valve member with a second spring in a predetermined second direction opposite to said predetermined first direction,
• said method further comprising steps of:
• 3. storing a plurality of relations between a pre-load and a target temperature of said water mixture;
• 4. based on inputs of predetermined data, selecting a first of said plurality of relations between the pre-load and the target temperature stored in said step 3;
• and
• 5. adjusting the pre-load of at least one spring of said first spring and said second spring and setting the pre-load equal to an initial value corresponding to a target temperature, based on said first relation selected in said step 4.