Suction device for fixing objects by suction by means of negative pressure, having a valve device comprising: - a valve housing, which includes a valve interior and has a supply connection for connection to a negative pressure supply and a suction side, - a flexible partition which extends in such a way that a control chamber extends into the valve housing on one side of the flexible partition and in that the suction side lies on the other side of the flexible partition, the control chamber being connected to the supply connection and the control chamber being connected to the suction side via a throttle passage in such a way that, during free suction, when the suction side is in a free inflow state, a flow path is provided from the suction side through the throttle passage into the control chamber and continues from the control chamber through the supply connection, and the throttle passage being designed in such a way that a flow resistance for flows along the flow path through the throttle passage is defined in such a way that, during free suction, when the suction side is in a free inflow state, a negative pressure with respect to the suction side occurs in the control chamber due to the flow resistance, and the flexible partition being designed in such a way that it is deformable due to the negative pressure which occurs in the control chamber during free suction, a sealing projection protruding into the interior of the control chamber and an associated sealing seat being provided inside the control chamber, the sealing projection and the sealing seat being arranged in such a way that, when the flexible partition is deformed during free suction, the sealing projection comes to rest against the sealing seat, and the sealing projection and the sealing seat being designed in such a way that, when the sealing projection rests against the sealing seat, the flow path through the throttle passage into the control chamber is interrupted inside the control chamber, the throttle passage being designed as a channel which extends through the flexible partition and opens into the control chamber via a mouth opening, characterized in that the sealing projection and the sealing seat are arranged in such a way that when the sealing projection rests against the sealing seat, the mouth opening is closed inside the control chamber. - a valve housing, which includes a valve interior and has a supply connection for connection to a negative pressure supply and a suction side, - a flexible partition which extends in such a way that a control chamber extends into the valve housing on one side of the flexible partition and in that the suction side lies on the other side of the flexible partition, the control chamber being connected to the supply connection and the control chamber being connected to the suction side via a throttle passage in such a way that, during free suction, when the suction side is in a free inflow state, a flow path is provided from the suction side through the throttle passage into the control chamber and continues from the control chamber through the supply connection, and the throttle passage being designed in such a way that a flow resistance for flows along the flow path through the throttle passage is defined in such a way that, during free suction, when the suction side is in a free inflow state, a negative pressure with respect to the suction side occurs in the control chamber due to the flow resistance, and the flexible partition being designed in such a way that it is deformable due to the negative pressure which occurs in the control chamber during free suction, a sealing projection protruding into the interior of the control chamber and an associated sealing seat being provided inside the control chamber, the sealing projection and the sealing seat being arranged in such a way that, when the flexible partition is deformed during free suction, the sealing projection comes to rest against the sealing seat, and the sealing projection and the sealing seat being designed in such a way that, when the sealing projection rests against the sealing seat, the flow path through the throttle passage into the control chamber is interrupted inside the control chamber, the throttle passage being designed as a channel which extends through the flexible partition and opens into the control chamber via a mouth opening, characterized in that the sealing projection and the sealing seat are arranged in such a way that when the sealing projection rests against the sealing seat, the mouth opening is closed inside the control chamber.