JPS6148634B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a diaphragm pump for pumping fluids such as liquids and slurries.

BACKGROUND ART Conventionally, non-contact positive displacement diaphragm pumps have been used for liquids, slurries, etc. that cannot be pumped by gear pumps, piston pumps, etc. As this type of diaphragm pump, a flat diaphragm pump using a thick-film flat diaphragm 9B that can withstand high pressure is known, as shown in FIGS. 6 and 7. The pump operates by expanding and contracting and bending the thick flat diaphragm 9B by the forward and backward movements of the piston 14B, so the operating stroke of the diaphragm 9B is limited to a small value and the diaphragm If the capacity of the pump decreases and the cycle of forward and backward movement of the diaphragm becomes faster, the durability of the diaphragm becomes significantly worse, resulting in a shortened lifespan of the diaphragm pump. In addition, in order to eliminate the drawbacks of the flat diaphragm pump, as shown in FIG. 5, a thin film grooved diaphragm 9A is used to prevent the diaphragm from expanding and contracting, and the diaphragm can withstand high-speed cycles. However, in such a diaphragm pump, when the piston 14A is moved forward to create positive pressure in the pump chamber 11A, the groove 9aA of the grooved diaphragm 9A is moved in the direction shown by the solid line (opposite to the pump chamber side). direction), and when the piston 14A is moved backward to create negative pressure in the pump chamber 11, the groove 9 of the grooved diaphragm 9A
Since aA bulges in the direction shown by the dotted line (towards the pump chamber), when the piston 14A etc. repeats reciprocating motion, the grooves of the diaphragm alternately reverse and bend, resulting in poor durability, and furthermore, the volume change inside the pump chamber is reduced. The drawback was that the volumetric efficiency of the diaphragm pump decreased. SUMMARY OF THE INVENTION Therefore, the present invention aims to eliminate the above-mentioned drawbacks and provide a diaphragm pump that can increase the durability of the diaphragm pump and can significantly improve pump performance.

Embodiments of the present application will be described below with reference to the drawings. 1
1 is a pump case in which a pump hole 2, a suction hole 3, and a discharge hole 4 are formed, respectively. 5 and 6 are check valves provided midway between the suction hole 3 and the discharge hole 4, respectively, and are composed of valve seats 5a, 6a, valve bodies 5b, 6b, and valve body receiving pieces 5c, 6c. There is. 7 is a suction port, and 8 is a discharge port. Reference numeral 9 denotes a diaphragm whose outer periphery is watertightly fixed to the pump case 1 over the entire circumference so as to close the pump hole 2. In the drawing, the diaphragm is sandwiched between the pump body 10 which is fastened to the pump case 1 and the pump case 1. It is fixed by being This diaphragm 9 has an annular groove portion 9a that swells toward the pump body 10 side.
is formed. 11 is a pump chamber formed within the pump hole 2 by the diaphragm 9; 12;
is an air hole formed in the pump body 10. 13 is the sliding hole 10a of the pump body 10
A piston rod is slidably inserted into the piston rod, and is reciprocated in the direction of the arrow by an appropriate reciprocating drive source 20 such as a crank mechanism rotated by a pneumatic or hydraulic cylinder or an electric motor. It's summery. A piston 14 is integrally formed at one end of the piston rod 12, and a flange 15 in the pump chamber 11 is attached to the tip end of the piston, and the flange 15 in the pump chamber 11 is clamped to the center of the diaphragm 9 by a tightening bolt (not shown). The diaphragm 9 is connected to the center of the diaphragm 9 by this. 16 is the above flange 15
A shielding member integrally formed with the diaphragm 9 forms an annular fluid storage chamber 17 between the pump case 1 and the pump case 1, and forms a main pump chamber 18 between the pump case 1 and the pump case 1. The shielding member 16 is formed so that its outer diameter D ₃ is somewhat smaller than the inner diameter D 1 of the pump hole 2 so as to have an appropriately sized gap 19 between the shielding member 16 and the inner surface of the pump case ₁ . The size of the gap 19 between the outer peripheral surface of the shielding member 16 and the inner surface of the pump case 1, that is, the size of the outer diameter D ₃ of the shielding member 16 and the inner diameter D ₁ of the pump hole 2, is determined by the pressure inside the fluid storage chamber 17. Piston 14
When the diaphragm 9 moves forward as the diaphragm 9 moves forward, the pressure becomes lower than the pump discharge pressure in the main pump chamber 18, and when the diaphragm 9 moves backward, the pressure becomes higher than the pump suction pressure in the main pump chamber 18. , is set to an appropriate value depending on the viscosity of the fluid to be pumped and the reciprocating speed of the piston 14. The shielding member 16 may be formed separately from the flange 15 and later integrally attached to the flange 15 with bolts or the like, or an annular plate may be attached to the flange 15.
5 may be configured such that it is rotatably mounted with its movement in the reciprocating direction restricted.

In the case of the above configuration, when it is desired to use this to pump fluid, the reciprocating drive source 20 is driven to cause the piston 14 to reciprocate. Due to this reciprocating movement of the piston 14, the center portion of the diaphragm 9 and the flange 15 are moved forward and backward by a predetermined amount, and positive pressure and negative pressure are alternately generated in the main pump chamber 18. That is, the center part of the diaphragm 9 and the flange 1
When the main pump chamber 18 is moved backward, the volume of the main pump chamber 18 increases, so a negative pressure is generated in the main pump chamber 18,
As a result, fluid sucked from the suction port 7 flows into the main pump chamber 18 through the check valve 5.
In this case, the check valve 6 in the discharge hole 4 is closed. Next, the center part of the diaphragm 9 and the flange 1
5 is moved forward, the volume of the main pump chamber 18 decreases, so a positive pressure is generated in the main pump chamber 18, which closes the check valve 5 in the suction hole 3 and closes the check valve in the discharge hole 4. 6 opens and main pump chamber 1
The fluid in 8 is discharged to the outside from the discharge port 8,
It is supplied to a predetermined location. The fluid is continuously pumped by repeating the above operations. In the case of the above operation, when the piston 14 is moved to the forward end, the second
As shown in the figure, when the shielding member 16 is largely separated from the groove 9a of the diaphragm 9 to increase the volume of the fluid reservoir 17, and when the piston 14 is moved to the reverse end, the shielding member 16 as shown in FIG. 16 approaches the groove 9a of the diaphragm 9 to reduce the volume of the fluid reservoir 17, and as the piston 14 reciprocates, the volume of the fluid reservoir 17 changes. Therefore, when the piston 14 is moved forward and the volume of the main pump chamber 18 is reduced and the pressure within the main pump chamber 18 is increased, the volume within the fluid storage chamber 17 is expanded as described above, so that the fluid The pressure in the reservoir chamber 17 becomes lower than the pressure in the main pump chamber 18, and the pressure applied to the diaphragm 9 becomes lower than the pump discharge pressure, causing the fluid in the main pump chamber 18 to flow between the inner surface of the pump case 1 and the shielding member 16. The fluid flows into the fluid storage chamber 17 through the gap 19 between the fluid and the outer peripheral surface. In addition, the piston 14
When the main pump chamber 18 is moved backward and the volume of the main pump chamber 18 is expanded and the pressure inside the main pump chamber 18 becomes negative pressure, the volume inside the fluid reservoir chamber 17 is reduced as described above and the fluid reservoir chamber 17 is Since the fluid inside is discharged from the gap 19 into the main pump chamber 18, the pressure inside the fluid storage chamber 17 is increased and does not become a negative pressure, and as a result, a weak positive pressure is applied to the diaphragm 9. Therefore, even if the pressure inside the main pump chamber 18 becomes negative, the groove 9a of the diaphragm 9 remains as shown in FIG.
is not reversed. When fluid is pumped by moving the diaphragm 9 back and forth in this way, the bulge of the groove 9a of the diaphragm 9 is always maintained in the same direction, which reduces damage to the diaphragm 9 and increases the discharge capacity of the pump. Furthermore, when fluid is pumped as described above, there is a gap 19 between the shielding member 16 and the inner surface of the pump case 1, so even when pumping slurry or the like, galling may occur between the shielding member 16 and the pump case 1. can be prevented.

In addition, the inner diameter of the pump hole 2 is D ₁ , and the piston 14 is
When the outer diameter of the flange 15 is D ₂ and the operating stroke of the piston 14 is L, the amount of change in the volume of the main pump chamber 18 V ₁ is V ₁ = D ₁ ²・π・L/4, The volume change amount V ₂ is approximately expressed as V ₂ ≒ (D ₁ ² - D ₂ ² )・π・L/8 The pump discharge amount V ₃ is approximately expressed as V ₃ ≒ V ₁ − V ₂ = (D ₁ ² + D ₂ ² )・π・L/8.

As described above, in this invention, the shielding member 1
6 and the diaphragm, and when the pressure in the pump chamber 11 increases by moving the diaphragm forward, the volume of the fluid reservoir 17 increases as the shielding member 16 moves forward, and the volume of the fluid reservoir 17 increases. becomes lower than the pressure in the pump chamber 11, and the diaphragm moves backward, causing the pressure in the pump chamber 1 to decrease.
1 becomes a negative pressure, the volume of the fluid storage chamber 17 decreases due to the retreat of the shielding member 16, and the pressure therein becomes higher than the pressure in the pump chamber 11. Therefore, when the diaphragm 9 is moved forward. In both cases, the pressure applied to the diaphragm 9 can be reduced. This means that when designing a diaphragm pump,
By reducing the thickness of the diaphragm membrane, the operating stroke and operating speed of the diaphragm can be increased, which has the effect of significantly improving the performance of the diaphragm pump.

Furthermore, even if the operating stroke and operating speed of the diaphragm can be increased as described above,
Since the force applied to the diaphragm during operation is reduced, damage to the diaphragm during operation can be reduced and the durability of the diaphragm can be improved, which has the effect of extending the life of the diaphragm pump. There is.

Furthermore, even if the fluid reservoir is formed between the shielding member and the diaphragm as described above, the shielding member must be formed with a gap between it and the inner surface of the pump case. Therefore, when used, like conventional diaphragm pumps, it can be used to pump fluids, slurries, etc. that cannot be pumped with general gear pumps, piston pumps, etc.

[Brief explanation of the drawing]

The drawings show an embodiment of the present application, and FIG. 1 is a longitudinal sectional view, FIGS. 2 and 3 are partially enlarged sectional views showing the operating state, and FIG. 4 is a sectional view taken along the - line in FIG. 5, 6, and 7 are cross-sectional views showing conventional examples. 1...Pump case, 9...Diaphragm, 1
1... pump chamber, 14... piston, 15... flange, 16... shielding member, 17... fluid reservoir chamber,
19...Gap.

Claims (1)

[Claims] 1 The outer peripheral part of the diaphragm is fixed to the inner surface of the pump case to form a pump chamber on one side thereof, and the central part of the diaphragm is sandwiched between a flange provided in the pump chamber and a piston outside the pump chamber, and the above-mentioned In a diaphragm pump in which the diaphragm can be moved forward and backward toward the pump chamber by reciprocating the piston, a shielding member is integrally provided around the flange with a gap left between it and the inner surface of the pump case. The shielding member is provided with surrounding equipment, and the surrounding state is such that the shielding member is spaced apart from the diaphragm so that a fluid reservoir is formed between the shielding member and the diaphragm, and
The pressure inside this fluid reservoir becomes lower than the pump discharge pressure when the volume of the fluid reservoir increases as the diaphragm moves forward, and when the volume of the fluid reservoir decreases as the diaphragm moves backward. A diaphragm pump characterized in that the size of the gap between the shielding member and the inner surface of the pump case is set so that the pressure is higher than the pump suction pressure.