US-12623463-B2 - Piezoelectric pump, liquid discharge head, and liquid discharge apparatus

US12623463B2US 12623463 B2US12623463 B2US 12623463B2US-12623463-B2

Abstract

A piezoelectric pump, for causing the flow of a liquid, including a piezoelectric member driven by applying a voltage, a diaphragm which is deformed by the driving of the piezoelectric member, an adhesive member which bonds the piezoelectric member and the diaphragm together, and an urging member that urges the piezoelectric member toward the diaphragm.

Inventors

Soji Kondo
Masashi Ogawa
Kimiyuki Hayasaki
Naozumi Nabeshima
Keiichiro Tsukuda

Assignees

CANON KABUSHIKI KAISHA

Dates

Publication Date: 20260512
Application Date: 20230308
Priority Date: 20220314

Claims (17)

1 . A liquid discharge head comprising: a discharge port that discharges liquid; a discharge element that generates energy for discharging the liquid from the discharge port; a pressure chamber in which the discharge element is disposed; a first channel connected to the pressure chamber to supply the liquid to the pressure chamber; a second channel connected to the pressure chamber; and a piezoelectric pump that makes the liquid in the second channel flow into the first channel; wherein the piezoelectric pump includes: a piezoelectric member driven by application of a voltage; a diaphragm deformed by driving of the piezoelectric member; an adhesive member bonding the piezoelectric member and the diaphragm together; an urging member that urges the piezoelectric member toward the diaphragm; and a drive circuit board, and wherein a gap between the drive circuit board and the piezoelectric member is set shorter than a free length of the urging member.
2 . The liquid discharge head according to claim 1 , wherein the discharge element generates energy for discharging the liquid by heating the liquid.
3 . The liquid discharge head according to claim 1 , further comprising a bypass channel that communicates between the first channel and the second channel not via the pressure chamber.
4 . The liquid discharge head according to claim 3 , wherein the second channel includes a second pressure adjusting unit that adjusts pressure of the liquid in the second channel, and wherein one end of the bypass channel communicates with the second pressure adjusting unit.
5 . The liquid discharge head according to claim 1 , further comprising: an inflow channel through which the liquid to be supplied to the pressure chamber flows into the first channel, wherein the first channel includes a first pressure adjusting unit that adjusts pressure of the liquid in the first channel, wherein the inflow channel is connected to the first channel, and wherein the first pressure adjusting unit communicates with the inflow channel.
6 . The liquid discharge head according to claim 1 , wherein the piezoelectric pump includes a drive circuit board, and wherein the urging member is fixed to the drive circuit board.
7 . The liquid discharge head according to claim 1 , wherein the urging member comprises an elastic member.
8 . The liquid discharge head according to claim 1 , wherein the elastic member comprises a spring member.
9 . The liquid discharge head according to claim 1 , further comprising: a supporting member supporting the diaphragm, the supporting member and the diaphragm forming a pump chamber therebetween; a supply port communicating with the pump chamber to supply liquid to the pump chamber; and a discharge port communicating with the pump chamber to discharge the liquid in the pump chamber, wherein, in use, the pump chamber extends in a vertical direction, and the discharge port is disposed higher than the supply port.
10 . The liquid discharge head according to claim 1 , wherein, in use, the discharge port is disposed higher than a center of a pump chamber in a vertical direction.
11 . A liquid discharge head comprising: a discharge port that discharges liquid; a discharge element that generates energy for discharging the liquid from the discharge port; a pressure chamber in which the discharge element is disposed; a first channel connected to the pressure chamber to supply the liquid to the pressure chamber; a second channel connected to the pressure chamber; and a piezoelectric pump that makes the liquid in the second channel flow into the first channel; wherein the piezoelectric pump includes: a piezoelectric member driven by application of a voltage; a diaphragm deformed by driving of the piezoelectric member; an adhesive member bonding the piezoelectric member and the diaphragm together; an urging member that urges the piezoelectric member toward the diaphragm; and a metal plate fixed to the piezoelectric member, and wherein the adhesive member bonds the piezoelectric member and the diaphragm together via the metal plate.
12 . The liquid discharge head according to claim 11 , wherein the metal plate has a larger area than the piezoelectric member.
13 . The liquid discharge head according to claim 11 , wherein the piezoelectric member, the metal plate, the adhesive member, and the diaphragm are disposed in this order, and wherein the urging member urges the metal plate toward the diaphragm via the piezoelectric member.
14 . The liquid discharge head according to claim 11 , wherein a gap between the drive circuit board and the metal plate is shorter than the free length of the urging member.
15 . A liquid discharge head comprising: a discharge port that discharges liquid; a discharge element that generates energy for discharging the liquid from the discharge port; a pressure chamber in which the discharge element is disposed; a first channel connected to the pressure chamber to supply the liquid to the pressure chamber; a second channel connected to the pressure chamber; a piezoelectric pump that makes the liquid in the second channel flow into the first channel; wherein the piezoelectric pump includes: a piezoelectric member driven by application of a voltage; a diaphragm deformed by driving of the piezoelectric member; an adhesive member bonding the piezoelectric member and the diaphragm together; an urging member that urges the piezoelectric member toward the diaphragm; a metal plate fixed to the piezoelectric member; and a drive circuit board configured to apply a voltage to the piezoelectric member, wherein the urging member includes a first urging member and a second urging member that contain an electrically conductive material and that electrically connect with the drive circuit board, and wherein the first urging member urges the piezoelectric member toward the metal plate, and the second urging member urges the metal plate toward the diaphragm.
16 . The liquid discharge head according to claim 15 , wherein the first urging member has a diameter less than a diameter of the piezoelectric member, and wherein the second urging member has a diameter greater than the diameter of the piezoelectric member and less than a diameter of the metal plate.
17 . The liquid discharge head according to claim 15 , wherein the first urging member and the second urging member are fixed and connected to the drive circuit board.

Description

BACKGROUND Field of the Disclosure The present disclosure relates to piezoelectric pumps, liquid discharge heads, and liquid discharge apparatuses. Description of the Related Art Piezoelectric pumps in the related art are known to function as pumps in which application of a voltage to a piezoelectric actuator in which a piezoelectric member is fixed to a metal plate causes vibration in the piezoelectric actuator, and the vibration is transmitted to a diaphragm. For example, Japanese Patent Laid-Open No. 2008-180161 discloses a piezoelectric pump in which a metal plate is bonded to a diaphragm with an adhesive. In the field of ink-jet printers, some liquid discharge apparatuses circulate liquid in a liquid discharge head to prevent ink thickening in the vicinity of discharge ports. For example, a known liquid discharge apparatus is equipped with a piezoelectric pump in the liquid discharge head to circulate the ink in the liquid discharge head. Integrating the liquid discharge head and the piezoelectric pump for circulating the ink allows reduction in the size of the liquid discharge apparatus. However, if the piezoelectric pump disclosed in Japanese Patent Laid-Open No. 2008-180161 is installed in, for example, a liquid discharge apparatus, the adhesive interface of the adhesive that bonds the diaphragm and the metal plate together can be separated. Even if the diaphragm is bonded to the piezoelectric member without using the metal plate, the adhesive interface can be separated. This is because the adhesive and, for example, ink, are separated by the diaphragm, but the ink component may pass through the diaphragm into the adhesive interface between the diaphragm and the metal plate or the piezoelectric member. The intrusion of the ink component into the adhesive interface separates the adhesive interface, making the displacement of the piezoelectric member less prone to be transmitted to the diaphragm. This may decrease the flow rate of the circulating ink, causing discharge failure due to the ink thickening in the vicinity of the nozzles. SUMMARY The present disclosure provides a piezoelectric pump in which separation of the adhesive interface of an adhesive that bonds a metal plate or a piezoelectric member and a diaphragm together can be prevented, and a liquid discharge head and a liquid discharge apparatus including such a piezoelectric pump. A piezoelectric pump according to a first aspect of the present disclosure is configured to make liquid flow. The piezoelectric pump includes a piezoelectric member driven by application of a voltage, a diaphragm deformed by driving of the piezoelectric member, an adhesive member bonding the piezoelectric member and the diaphragm together, and an urging member that urges the piezoelectric member toward the diaphragm. A piezoelectric pump according to a second aspect of the present disclosure is configured to make liquid flow. The piezoelectric pump includes a piezoelectric member driven by application of a voltage, a metal plate fixed to the piezoelectric member, a diaphragm deformed by driving of the piezoelectric member, an adhesive member bonding the metal plate and the diaphragm together, and an urging member that urges the metal plate toward the diaphragm. Further features of the present disclosure will become apparent from the following description of embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a front view of a piezoelectric pump of a first embodiment. FIG. 1B is a side view of the piezoelectric pump. FIG. 1C is a back view of the piezoelectric pump. FIG. 2 is a cross-sectional view of the piezoelectric pump. FIG. 3A is an exploded perspective view of the drive unit of the piezoelectric pump seen from the back. FIG. 3B is an exploded perspective view of the drive unit of the piezoelectric pump seen from the front. FIG. 4 is a perspective view of the drive unit of the piezoelectric pump. FIG. 5 is a cross-sectional view of the piezoelectric pump in which the urging member is a rubber member. FIG. 6A is an exploded perspective view of the piezoelectric pump seen from the back in which the diaphragm and the piezoelectric member are bonded. FIG. 6B is an exploded perspective view of the piezoelectric pump seen from the front in which the diaphragm and the piezoelectric member are bonded. FIG. 7 is a cross-sectional view of a piezoelectric pump of a second embodiment. FIG. 8 is an exploded perspective view of the drive unit of the piezoelectric pump. FIG. 9 is a perspective view of the drive unit of the piezoelectric pump. FIG. 10 is an exploded perspective view of the piezoelectric pump in which the urging member is a leaf spring. FIG. 11 is an exploded perspective view of the piezoelectric pump in which the urging member is a large-diameter spring. FIG. 12 is a perspective view of the dive unit of the piezoelectric pump in which the urging member is a large-diameter spring. FIG. 13A is a schematic diagram o