Valve member and milking machine

A breast pump comprising:

• a storage container configured to store milk;
• a hood configured to be applied to a breast;
• an internal passage configured to temporarily store expressed milk and to connect a milk extraction opening defined by the hood to the storage container;
• a valve member configured to cause the milk temporarily stored in the internal passage to flow out to the storage container;
• and
• a negative pressure creation mechanism configured to alternately create a negative pressure state and a normal pressure state in the internal passage, wherein the valve member is configured to allow milk from the hood to be temporarily stored in the internal passage when the breast pump is in the negative pressure state, and to allow the milk stored in the internal passage to flow out to the storage container when the breast pump is in the normal pressure state, and wherein the valve member includes:
• a cap configured to be attached to the breast pump, the cap including a partition wall separating a first space on an inflow side of the milk from a second space on an outflow side of the milk, and a through-hole disposed in the partition wall to connect the first space to the second space, wherein the cap includes an outer circumference wall, and wherein a portion of the outer circumference wall defining the second space includes a thick section that has a first thickness and bulges inward and a thin section that is thinner than the thick section and has a second thickness;
• and
• a valve body disposed in the second space, the valve body being configured to close the through-hole when the negative pressure state is created, and to open the through-hole when the normal pressure state is established.

A breast pump comprising:

• a storage container configured to store milk;
• a hood configured to be applied to a breast;
• an internal passage configured to temporarily store expressed milk and to connect a milk extraction opening defined by the hood to the storage container;
• a valve member configured to cause the milk temporarily stored in the internal passage to flow out to the storage container;
• and
• a negative pressure creation mechanism configured to alternately create a negative pressure state and a normal pressure state in the internal passage, wherein the valve member is configured to allow milk from the hood to be temporarily stored in the internal passage when the breast pump is in the negative pressure state, and to allow the milk stored in the internal passage to flow out to the storage container when the breast pump is in the normal pressure state, and wherein the valve member includes:
• a cap attached to the breast pump, the cap including a partition wall separating a first space on an inflow side of the milk from a second space on an outflow side of the milk, and a through-hole disposed in the partition wall to connect the first space to the second space, wherein the cap includes an outer circumference wall, and wherein a portion of the outer circumference wall defining the second space includes a thick section that has a first thickness and bulges inward and a thin section that is thinner than the thick section and has a second thickness;
• and
• a valve body disposed in the second space, the valve body being configured to close the through-hole when the negative pressure state is created, and to open the through-hole when the normal pressure state is established, wherein the valve body includes a plate-shaped portion for closing the through-hole, and an attachment projection extending from the plate-shaped portion, and wherein the partition wall includes an attachment hole that is engaged with the attachment projection.