Pressure detection device
The flow channel unit includes: a pair of end flow channels disposed at an inflow port and an outflow port, respectively, and extending along in flow direction; a center flow channel including a pressure receiving portion having a thin film shape and disposed at a position sandwiched between the pair of end flow channels, a distance from an inner peripheral surface of the pressure receiving portion to an outer peripheral surface thereof being shorter than a distance from an inner peripheral surface of the pair of end flow channels to an outer peripheral surface thereof. The pair of end flow channels and the center flow channel are integrally formed of a flexible resin material, and the pressure detection portion is disposed such that the pressure of the fluid circulated through a flow channel is transmitted via the pressure receiving portion.
1. A pressure detection device comprising:
a pressure detection unit configured to detect a pressure to be transmitted to a pressure detection portion; and
a flow channel unit including a flow channel body provided with a flow channel through which a fluid is circulated along a circulation direction from an inflow port to an outflow port, wherein
the flow channel body includes:
a pair of end flow channels disposed at the inflow port and the outflow port, respectively; and
a center flow channel including a pressure receiving portion having a thin film shape and disposed at a position sandwiched between the pair of end flow channels, a distance from an inner peripheral surface of the pressure receiving portion to an outer peripheral surface thereof being shorter than a distance from an inner peripheral surface of the pair of end flow channels to an outer peripheral surface thereof,
the pair of end flow channels and the center flow channel are integrally formed of a flexible resin material, and
the pressure detection portion is disposed in such a manner that the pressure of the fluid circulated through the flow channel is transmitted via the pressure receiving portion.
2. The pressure detection device according to claim 1 , wherein
a distance from an inner peripheral surface in a partial region of the center flow channel in a circumferential direction about the circulation direction to an outer peripheral surface thereof is shorter than a distance from an inner peripheral surface in another region of the center flow channel to an outer peripheral surface thereof, and
the partial region is set as the pressure receiving portion.
3. The pressure detection device according to claim 1 , wherein
the center flow channel has a flow channel sectional area larger than that of the pair of end flow channels,
a pair of connecting flow channels is formed to connect an end of the pair of end flow channels that is located closer to the center flow channel and both ends of the center flow channel,
the pair of end flow channels, the center flow channel, and the pair of connecting flow channels are integrally formed of a flexible resin material, and
the pair of connecting flow channels is formed in such a manner that a flow channel sectional area of the pair of connecting flow channels gradually increases toward the both ends of the center flow channel.
4. The pressure detection device according to claim 1 , wherein
the pressure detection unit includes:
a pressure sensor including the pressure detection portion; and
a pressure transmission portion disposed in a state where one end of the pressure transmission portion is in contact with the pressure detection portion and the other end of the pressure transmission portion is in contact with the pressure receiving portion, the pressure transmission portion being configured to transmit the pressure of the fluid received by the pressure receiving portion to the pressure detection portion, and
the pressure transmission portion displaces the pressure receiving portion toward the flow channel and is disposed in a state of receiving an urging force directed to the pressure detection portion from the pressure receiving portion.
5. The pressure detection device according to claim 4 , wherein
the flow channel unit is provided with a recess in which the pressure receiving portion is disposed,
the pressure sensor is disposed in contact with the flow channel unit so as to cover the recess, and
a communication flow channel is formed to allow an inside space and an outside space to communicate with each other, the inside space and the outside space being partitioned by the recess and the pressure sensor.
6. The pressure detection device according to claim 4 , wherein
the pressure transmission portion includes:
a first pressure transmission member disposed in contact with the pressure receiving portion; and
a second pressure transmission member disposed in contact with the pressure detection portion, and
a contact area between the second pressure transmission member and the pressure detection portion is smaller than a contact area between the first pressure transmission member and the pressure receiving portion.
7. The pressure detection device according to claim 6 , wherein the first pressure transmission member is a member formed into a spherical shape projecting toward the pressure receiving portion.