The invention discloses an automatic
pressure control device capable of preventing explosion of a
hot water bottle constantly. The automatic
pressure control device disclosed by the invention is characterized in that a
pressure reduction cabin is arranged outside a bag body of a common
hot water bottle, and the
pressure reduction cabin and the bag body are connected through a
pressure controller; the
pressure controller comprises a tube-shaped shell, a ball baffle cover, and a sealing ball, a
piston and a spring which are arranged in the shell; a vent hole and an air inlet are formed at the
tail end of the shell and the ball baffle cover, respectively; an air bleeding valve is arranged on the
pressure reduction cabin; under a
normal state, the sealing ball baffles the air inlet on the ball baffle cover which is connected with the shell under action of the spring, and the
pressure controller is in a
closed state; when pressure intensity in the
hot water bottle body is increased to a rated value due to heating or an external force, the sealing ball is pushed away from the air inlet, air or redundant liquid in the
bottle enters the pressure controller from the air inlet, then enters the pressure reduction cabin via the vent hole, and is finally discharged at the air bleeding valve till
internal pressure and
external pressure are balanced, and the air inlet is sealed again by the sealing ball due to action of the spring. The automatic
pressure control device disclosed by the invention has the greatest characteristics of being capable of controlling pressure intensity in the hot
water bottle to be within a safe range constantly so as to ensure safety of a user.