[0015] Reference Figure 1-3 As shown, the present invention includes a pump body 21, a pump cover 20, a piezoelectric vibrator 19, and a vibrating diaphragm 18. The material of the pump body 21 is silicon, the pump cover 20 is directly above the pump body 21, and the material of the pump cover 20 is glass. The pump body 21 and the pump cover 20 are tightly bonded together by a vacuum oxygen plasma bonding process.
[0016] Such as figure 2 , The pump cover 20 is processed with the filling pump port 1, the upper pump cavity 5, the first pump inlet 15, the second pump inlet 17, and the pump outlet 13. The height of the structure processed on the pump cover 20 is equal to that of the pump cover 20 The upper and lower heights are the same.
[0017] Such as image 3 , The pump body 21 is processed into the pump cavity 2, the pump pipe 3, the lower pump cavity 4, the wall part II, the first inlet direct-flow pipe 10, the first pump inlet buffer cavity 14, and the second inlet direct-flow pipe 11, The second pump inlet buffer chamber 16 and the outlet direct current pipe 9, the pump outlet buffer chamber 12. The upper and lower heights of the structure processed on the pump body 21 are all the same height as the pump body 21, and the longitudinal sections are all rectangular, and they are all distributed symmetrically about the horizontal central axis M in the left and right direction where the pump body 21 is located. The structure on the pump body 21 can be processed by a molding method, and the structure on the pump cover 20 can be processed by a laser processing technology.
[0018] The vibrating diaphragm 18 is made of brass (or other elastic materials) and is fixed directly above the upper pump cavity 5 by an adhesive. The piezoelectric vibrator 19 is a driving element, and the piezoelectric vibrator 19 is bonded to the upper surface of the vibrating diaphragm 18 by epoxy resin. The vertical center lines of the piezoelectric vibrator 19, the diaphragm 18, the upper pump cavity 4 and the lower pump cavity 5 are collinear.
[0019] The pumping cavity 2, the pumping pipe 3, the lower pump cavity 4 and the coanda part II are symmetrical from left to right along the left and right horizontal center line M of the pump body 23, and are connected in series and connected in sequence. The right end of the wall part II is respectively connected to the first pump inlet buffer cavity 14 via the first inlet direct current pipe 10, to the second pump inlet buffer cavity 12 via the second inlet direct pipe 11, and to the pump outlet buffer cavity 12 via the outlet direct pipe 9 . The horizontal center line in the left-right direction of the outlet direct current pipe 9 and the pump outlet buffer chamber 12 coincides with the left-right horizontal center axis M of the pump body 21. The first pump inlet buffer chamber 14 and the second pump inlet buffer chamber 16 are symmetrical about the left and right horizontal center axis M of the pump outlet buffer chamber 12, and the first inlet direct current pipe 10 and the second inlet direct current pipe 11 are about the pump outlet buffer chamber 9 The left and right horizontal central axis M is symmetrical in front and back.
[0020] The pump cavity 2 is directly below the pump port 1 and communicates with the pump port 1. The lower pump cavity 4 is directly below the upper pump cavity 5 and communicates with the lower pump cavity 4. The upper pump cavity 5 and the lower pump cavity 4 The horizontal cross section is circular and the inner diameter is equal, and the upper pump cavity 5 and the lower pump cavity 4 form the pump cavity of the micropump. The first pump inlet buffer cavity 14 is directly below the first pump inlet 15 and communicates with the first pump inlet 15, and the second pump inlet buffer cavity 16 is directly below the second pump inlet 17 and communicates with the second pump inlet 17, The pump outlet buffer cavity 12 is directly below the pump outlet 13 and communicates with the pump outlet 13.
[0021] See image 3 with Figure 4 , The wall part II is composed of buffer cavity 6, confluence cone 8 and blocking block 7. The left end of the converging cone 8 is a small end, and the right end is a big end. The left end of the buffer cavity 6 is connected with the lower pump cavity 4, and the right end is connected with the small end of the converging cone 8. The large ends of the converging cone 8 are respectively communicated with the left ends of the first inlet straight pipe 10, the second inlet straight pipe 11 and the outlet straight pipe 9 respectively. The right end of the first inlet direct flow pipe 10 is in communication with the first inlet buffer cavity 14, and the right end of the second inlet direct flow pipe 11 is in communication with the second inlet buffer cavity 16. The right end of the outlet direct-flow pipe 9 communicates with the outlet buffer cavity 12.
[0022] In the middle of the small end of the converging cone 8 is a blocking block 7, which separates the flow channel at the small end of the converging cone 8 into two identical narrow flow channels in the front and the back. The blocking block 7 is symmetrical with respect to the left and right horizontal central axis M of the pump body 21. The vertical height of the blocking block 7 is the same as the vertical height of the pump body 21 and is fixed on the bottom surface of the pump body 21. The block 7 is composed of a semicircular column on the left and a triangular column on the right. The front and rear side walls of the triangular column are tangent to the semicircular column, and the right end of the block 7 is the tip of the triangular column. The cross section of the block 7 is a shape where a semicircle and a triangle meet. The front and back sides of the triangle are tangent to the semicircle. The length of the left side of the triangle is equal to the diameter of the semicircle. The center of the semicircle of the block 7 is the confluence cone. 8 The center of the small end face.
[0023] The minimum width of the narrow flow channel at the small end of the converging cone 8 is d, and d is 100 μm-200 μm. The left and right lengths of the confluence cone 8 L 1 4~8 times the minimum width d of the narrow runner. The arc radius R of the block 7 is 1 to 2 times the minimum width d of the narrow flow channel, and the angle α of the triangle at the right end of the block 7 is 60°. The included angle θ between the first inlet direct flow tube 10, the second inlet flow tube 11 and the two ends of the confluence cone 8 is 60°. The front and rear widths of the first inlet dc tube 10, the second inlet dc tube 11 and the outlet dc tube 9 are equal, b, and b is equal to. The left and right lengths of the first inlet dc tube 10, the second inlet dc tube 11 and the outlet dc tube 9 are equal, and they are all L 2 , Request L 2 :d is 15:1. Radius of lower pump chamber 4 R c Ratio R to the minimum width d of narrow runner c :d is 25:1.
[0024] See Figure 5-6 As shown, when the present invention is working, after an alternating voltage signal (sine or rectangular wave signal) is applied to both ends of the piezoelectric vibrator 19, the piezoelectric vibrator 19 will undergo bending deformation and periodically vibrate up and down with the voltage frequency. This vibration drives the upper pump The fluid flow in cavity 5 and lower pump cavity 4 can be divided into discharge process and suction process: the discharge process is as Figure 5-6 Shown: when the piezoelectric vibrator 19 is excited by the external electric field and vibrates downward, the volume of the pump cavity decreases, so that the pressure in the pump cavity increases and is greater than the external pressure, so that the fluid is discharged from the pump cavity to the confluence through the buffer cavity 6 Conical tube 8 inside. Such as Figure 5 As shown, because the arc transition structure of the block 7 induces the jet to flow along the surface of the block 7, the proportion of the fluid discharged from the pump cavity into the outlet direct-flow pipe 9 is greatly increased, and at the same time, the confluence cone 8 is close to the inlet direct-flow pipe. The place formed two pairs of vortexes. In the period before the discharge stage, due to the weak entrainment strength of the vortex, the inlet and outlet direct current pipes simultaneously discharge fluid (such as Image 6 Shown), but as the entrainment strength of the vortex increases, the fluid is entrained from the first inlet direct current pipe 10 and the second inlet direct current pipe 11 into the outlet direct current pipe 9, such as Image 6 As shown, the discharge volume of the pump chamber in the discharge process is. The inhalation process is like Figure 7-8 As shown, when the piezoelectric vibrator 19 is excited by an external electric field and vibrates upward, the volume of the pump cavity increases, and the pressure in the pump cavity decreases and is less than the external pressure, so that fluid flows in simultaneously through the first pump inlet 15 and the second pump inlet 17 In the lower pump cavity 4. Since the vortex in the discharge stage still exists and the fluid entering from the inlet has a certain obstructive effect on the fluid entering the outlet, the fluid in the outlet through-flow pipe 9 is both discharged and sucked. During the period before the suction phase, the pump outlet 13 behaves as a discharged fluid, such as Figure 7 As shown, as the vortex weakens and disappears and the suction speed of the pump cavity increases, the pump outlet 13 appears as a suction fluid, such as Figure 8 As shown, the suction volume of the pump chamber in the suction process is. Suppose the instantaneous flow of pump outlet 13 is , Then the net flow of the pump outlet 13 in a cycle is , The volume change of the pump chamber is , So the volumetric efficiency of the block-type wall-attached jet valveless piezoelectric micropump is , Volumetric efficiency Up to 84.5%.
