JP4786950B2 - Diaphragm pump - Google Patents

Description

  The present invention relates to a diaphragm pump in which a pump chamber expands and contracts to perform a pump action by reciprocating a diaphragm using a motor as a drive source, and more particularly to a diaphragm pump that increases the pressure of fluid to be discharged.

  FIG. 4 is a longitudinal sectional view of a conventional diaphragm pump. A diaphragm pump denoted as a whole by the reference numeral 101 in FIG. 1 includes a case 2 formed in a substantially bottomed rectangular tube shape. The bottom 3 of the case 2 has an output shaft 5 through a hole 6 provided in the bottom 3. The motor 4 is fixed with a screw so that it faces the inside of the case 2. Reference numeral 7 denotes a crank base formed in a substantially small cylindrical shape. The crank base 7 is attached to the output shaft 5 of the motor 4, and a head 8a is hemispherical at a portion eccentric from the output shaft 5 of the crank base 7. The drive shaft 8 formed in is fixed in an inclined state with respect to the output shaft 5 of the motor 4. Reference numeral 9 denotes a driving body, which includes a boss 10 and a pair of driver elements 11A and 11B that protrude from the upper end of the boss 10 in the radial direction with a phase shift of 180 ° in the circumferential direction. It is configured. A bearing member 10a formed in a substantially cylindrical shape by a material having a lower coefficient of friction than the member forming the boss 10 is fitted and fixed to the center portion of the boss 10, and the center portion of the bearing member 10a is fixed. The drive shaft 8 is rotatably inserted into the shaft hole 10b.

  Reference numeral 12 denotes a diaphragm holder that is open at the bottom and is formed in a substantially box shape. The upper plate 13 has a pair of diaphragm portion holding holes 14A and 14B for holding diaphragm portions 16A and 16B of a diaphragm 15 to be described later. The diaphragm holder 12 and the case 3 are opposed to each other at their open ends. Reference numeral 15 denotes a diaphragm having two diaphragm portions 16A and 16B, and piston portions 17A and 17B are integrally formed on each diaphragm portion 16A and 16B. The diaphragm portions 16A and 16B of the diaphragm 15 are held in the diaphragm portion holding holes 14A and 14B of the diaphragm holder 12, respectively. In addition, the diaphragm 15 is held by the diaphragm holder 12 and the driving body 9 by attaching the lower ends of the piston portions 17A and 17B to the driving elements 11A and 11B of the driving body 9.

  Reference numeral 18 denotes a valve holder formed in a flat rectangular parallelepiped shape. The valve holder 18 holds the diaphragm 15 together with the diaphragm holder 12, and two first and second pumps are formed by the valve holder 18 and the diaphragm portions 16A and 16B. Chambers 19A and 19B are formed. Further, the valve holder 18 has a first suction passage 20A and a first discharge passage 21A communicating with the first pump chamber 19A, and a second suction passage 20B and a second discharge passage communicating with the second pump chamber 19B. Two discharge passages 21B are provided. The valve holder 18 is provided with first and second suction valve bodies 22A and 22B and first and second discharge valve bodies 23A and 23B. Among these, the first suction valve body 22A opens and closes the first suction passage 20A, and the first discharge valve body 23A opens and closes the first discharge passage 21A. On the other hand, the second suction valve body 22B opens and closes the second suction passage 20B, and the second discharge valve body 23B opens and closes the second discharge passage 21B.

  Reference numeral 25 denotes a cover body that is formed in a substantially box shape with an opening at the bottom that covers the valve holder 18, and a pair of partition walls 26, 26 project integrally from the cover body 25. The partition wall 26, the valve holder 18, and the lid body 25 are formed so that the suction space 27, the communication passage 28, and the discharge passage 29 are isolated from each other. The suction space 27 communicates with the first suction passage 20A, the communication passage 28 communicates with the first discharge passage 21A and the second suction passage 20B, and the discharge space 29 communicates with the second discharge passage 21B. Yes. In addition, a suction port 30 communicating with the suction space 27 is provided at one end of the lid body 25, and a cylindrical portion 31 is integrally projected at the other end, and a discharge space 29 is provided at the open end of the cylindrical portion 31. A discharge port 32 that communicates with the discharge port 32 is provided. The lid body 25 and the valve holder 18 are welded together, and the valve holder 18, the diaphragm holder 12, and the case 2 are integrated by a through screw (not shown).

  In such a configuration, when the motor 4 is driven to rotate the output shaft 5 and rotate the crank base 7 integrally, the drive shaft 8 rotates eccentrically around the output shaft 5 so as to change the tilt direction. Therefore, the two driver elements 11A and 11B of the driving body 9 are alternately swung up and down, and the two diaphragm portions 16A and 16B of the diaphragm 15 are also swung up and down alternately. When one diaphragm portion 16A moves downward, the first pump chamber 19A expands, so that the first pump chamber 19A is in a negative pressure state, and air flows from the suction port 30 through the first suction passage 20A. It is sucked into the first pump chamber 19A.

  When the output shaft 5 of the motor 4 further rotates, the expanded diaphragm portion 16A of the first pump chamber 19A moves upward, and the first pump chamber 19A contracts. Accordingly, the pressure in the first pump chamber 19A rises, and the air in the first pump chamber 19A is discharged to the communication passage 28 through the first discharge passage 21A. At this time, since the other diaphragm portion 16B is moved downward, the second pump chamber 19B expands and the second pump chamber 19B enters a negative pressure state. Therefore, the air discharged from the first pump chamber 19A to the communication passage 28 is sucked into the second pump chamber 19B through the second suction passage 20B. When the output shaft 5 of the motor 4 further rotates, the diaphragm portion 16B of the expanded second pump chamber 19B moves upward and the second pump chamber 19B contracts, so that the pressure in the second pump chamber 19B increases. The air in the second pump chamber 19B is discharged from the discharge port 32 via the discharge space 29 through the second discharge passage 21B.

Thus, by connecting the first pump chamber 19A and the second pump chamber 19B via the communication passage 28, the second pump chamber 19B has a discharge pressure from the first pump chamber 19A. Is added. For this reason, the discharge pressure of air discharged from the discharge port 32 of the diaphragm 101 is compared with the discharge pressure of air by a normal diaphragm pump that does not have a communication passage communicating between the first and second pump chambers. Become higher. (For example, refer to Patent Document 1).
JP 2001-82341 A (paragraphs “0048” to “0053”, FIG. 3)

  In the conventional diaphragm pump described above, since the air pressurized by the first pump chamber 19A is sucked into the second pump chamber 19B, the pressure in the second pump chamber 19B increases. Is maximum when the piston portion 17B of the second pump chamber 19B reaches bottom dead center. Therefore, when the piston portion 17B moves from the bottom dead center to the top dead center, that is, when the piston 17B is to be lifted by the driver 11B, the ceiling surface 10c of the shaft hole 10b of the drive body 9 and the sliding surface. A large load is applied between the head 8a of the drive shaft 8 that moves. For this reason, there is a problem in that durability is reduced due to generation of a large mechanical frictional force between the ceiling surface 10c and the head 8a.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a diaphragm pump having improved durability while increasing the discharge pressure.

In order to achieve this object, the invention according to claim 1 includes a rotating body to which an output shaft of a motor is fixed, and a drive shaft protruding in a state inclined to a portion eccentric from the output shaft of the rotating body. A drive body rotatably supported by the drive shaft, a diaphragm to which each diaphragm portion forming a plurality of pump chambers is attached to the drive body, a suction passage for sucking fluid into the pump chamber, A suction valve body for opening and closing the suction passage, a discharge passage for discharging the fluid in the pump chamber, a discharge valve body for opening and closing the discharge passage, and between adjacent pump chambers among the plurality of pump chambers A communication passage that sequentially connects the discharge passage and the suction passage, and reciprocally moves each diaphragm portion of the diaphragm via the drive shaft and the drive body following the rotation of the rotating body. In a diaphragm pump that pumps by expanding and contracting a chamber, a housing that houses the diaphragm and the diaphragm form a sealed drive chamber, and a part of the fluid that passes through the communication passage is driven by the diaphragm An introduction passage is provided for introduction into the chamber.

  The invention according to claim 2 is the invention according to claim 1, wherein a seal material formed of an elastic material is interposed between the motor and the housing, and an inner peripheral surface of the seal material is an output shaft of the motor. The hole which closely_contact | adheres to the outer peripheral surface of this is provided.

  According to the present invention, by introducing a part of the fluid passing through the communication passage into the sealed drive chamber, the pressure sucked inside the pump chamber and the pump chamber supplied to the outside of the pump chamber are supplied. And the pressure for pushing up are substantially the same so as to cancel each other. Therefore, when the piston part that pushes down or pushes up the pump chamber moves from the bottom dead center to the top dead center, that is, when the drive part tries to lift the diaphragm part, the drive body and the drive shaft that slides therewith During this period, a large load caused by the pressure sucked into the pump chamber is not applied. For this reason, since a big mechanical frictional force does not generate | occur | produce between a drive body and a drive shaft, durability improves.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a diaphragm pump 1 according to the present invention. In the figure, the same or equivalent members described in the prior art shown in FIG. 4 described above are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

  The diaphragm pump 1 according to the present invention is different from the conventional diaphragm pump 101 described above in that all of the air discharged from the first pump chamber 21A through the first discharge passage 20A to the communication passage 28 is second. Rather than being supplied into the pump chamber 21B, an introduction passage 35 for introducing a part into the back surface side of the second pump chamber 21B is provided.

  That is, the pore 13 a is provided at the center of the ceiling 13 of the diaphragm holder 12, the pore 15 a is provided at the center of the diaphragm 15, and the pore 18 a is provided at the center of the valve holder 18. These pores 13a, 15a, 18a communicate with each other to form the introduction passage 35. The introduction passage 35 communicates the communication passage 28 with the drive chamber 37 constituted by the housing 36 and the diaphragm 15 formed by the case 2 and the diaphragm holder 12.

  Another feature of the present invention is that the above-described drive chamber 37 that accommodates the diaphragm portions 16A and 16B, the drive body 9, and the crank base 7 is sealed. That is, a first sealing material 38 formed in a ring shape with rubber as an elastic material is interposed between the case 2 and the diaphragm holder 12, and an elastic material is provided between the motor 4 and the bottom portion 3 of the case 2. The second sealing material 39 formed in a disc shape with rubber is interposed.

  A shaft seal portion 40 is formed in the center portion of the second seal material 39 and is formed in an inverted mortar shape and provided with a shaft hole 40a in the ceiling portion. The output shaft of the motor 4 inserted through the shaft hole 40a is formed. The inner peripheral surface 40 b of the shaft hole 40 a is in close contact with the outer peripheral surface of the shaft 5, and the lower end portion of the output shaft 5 is covered with the shaft seal portion 40. Therefore, the space between the case 2 and the diaphragm holder 12 is airtight by the first sealing material 38, and the space between the motor 4 and the bottom 3 of the case 2 is airtight by the second sealing material 39. For this reason, the driving chamber 37 formed by the diaphragm 15 and the housing 36 is in a sealed state.

  With this configuration, when the motor 4 is driven and the output shaft 5 is rotated to rotate the crank base 7 integrally, the drive shaft 8 is eccentric so as to change the direction of inclination around the output shaft 5. Rotate. Therefore, the two driver elements 11A and 11B of the driving body 9 are alternately swung up and down, and the two diaphragm portions 16A and 16B of the diaphragm 15 are also swung up and down alternately. When one diaphragm portion 16A descends and rises, the first pump chamber 19A expands and contracts, so that the air sucked into the first pump chamber 19A through the first suction passage 20A becomes the first pump chamber 19A. It is discharged to the communication passage 28 through the discharge passage 21A.

  A part of the air discharged to the communication passage 28 is introduced into the drive chamber 37 through the introduction passage 35 because the introduction passage 35 is provided in the communication passage 28. As described above, since the drive chamber 37 is held in a sealed state, the pressure in the drive chamber 37 is substantially the same as the pressure in the expanded second pump chamber 19B. That is, the pressure in the second pump chamber 19B that acts to push down the piston portion 17B and the pressure in the drive chamber 37 that acts to push up the piston portion 17B cancel each other.

  Therefore, when the piston portion 17B that pushes down or pushes up the second pump chamber 19B moves from the bottom dead center to the top dead center, that is, when the piston 17B is to be lifted by the driver 11B, A large load may be applied between the ceiling 10b of the shaft hole 10a and the head 8a of the drive shaft 8 that slides on the shaft 10b due to the pressure sucked into the second pump chamber 19B. Absent. For this reason, since a large mechanical frictional force is not generated between the ceiling portion 10b of the shaft hole 10a of the drive body 9 and the head portion 8a of the drive shaft 8 that slides on the shaft portion 10b, durability is improved.

  FIG. 2 is a cross-sectional view showing the main part of the second embodiment of the present invention. In FIG. 2A, reference numeral 45 denotes a second sealing material formed in a disk shape by rubber, which is an elastic material, and a central portion has a diameter R2 smaller than the diameter R1 of the output shaft 5 of the motor 4. A formed hole 45a is provided. In such a configuration, the output shaft 5 of the motor 4 is inserted into the hole 45a of the second sealing material 45, and the second sealing material 45 is sandwiched between the motor 4 and the bottom portion 3 of the case 2, whereby the same As shown in FIG. (B), the inner peripheral surface 45b of the hole 45a is elastically deformed in the insertion direction of the output shaft 5 to be in close contact with the outer peripheral surface of the output shaft 5, and the gap between the motor 4 and the bottom 3 of the case 2 is It becomes airtight.

  FIG. 3 is a cross-sectional view showing the main part of the third embodiment of the present invention. The third embodiment is characterized in that the inner peripheral surface 45b of the hole 45a of the second sealing material 45 is brought into close contact with the outer peripheral surface of the output shaft 5 by surface contact. In this way, the inner peripheral surface 45b is brought into close contact with the outer peripheral surface of the output shaft 5 by surface contact, so that a higher airtight state is established between the motor 4 and the bottom 3 of the case 2.

  In the present embodiment, the fluid is described as air, but it can also be applied to a pump for liquid such as water. Moreover, although the example which provided two pump chambers 19A and 19B was demonstrated, it is applicable also to the pump which provided the three or more pump chambers in the circumferential direction in planar view. In that case, one first pump chamber of the plurality of pump chambers is communicated with the suction port 30, and the second pump chamber adjacent thereto is connected via the discharge valve body and the suction valve body. In this manner, the third, fourth, and Nth pump chambers are sequentially communicated by the communication passage 28, and the last Nth pump chamber and the discharge port 32 are communicated.

  In the present embodiment, the first seal member 38 and the second shield members 39 and 45 are interposed to make the drive chamber 37 a sealed space. However, the motor 4 and the case 2 The drive chamber 37 may be hermetically sealed by bonding the contact surface with the bottom 3 of the battery and the contact surface between the case 2 and the diaphragm holder 12 by adhesion or welding, in which case the first sealing material 38 and The second sealing materials 39 and 45 are not necessary. Further, the airtight state between the motor 4 and the drive chamber 37 may be increased by increasing the viscosity of the impregnating oil in the bearing in the motor 4 that rotatably supports the output shaft 5 of the motor 4. .

It is a longitudinal cross-sectional view of the diaphragm pump which concerns on this invention. It is sectional drawing which shows the principal part of the 2nd Embodiment of this invention. It is sectional drawing which shows the principal part of the 3rd Embodiment of this invention. It is a longitudinal cross-sectional view of the conventional diaphragm pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Diaphragm pump, 2 ... Case, 4 ... Motor, 7 ... Crank stand (rotary body), 8 ... Drive shaft, 8a ... Head, 9 ... Drive body, 10a ... Shaft hole, 10b ... Ceiling part, 11A, 11B ... Driver, 12 ... Diaphragm holder, 14A, 14B ... Diaphragm part holding hole, 15 ... Diaphragm, 16A, 16B ... Diaphragm part, 17A, 17B ... Piston part, 18 ... Valve holder, 19A ... First pump chamber, 19B ... Second pump chamber, 20A ... First suction passage, 20B ... Second suction passage, 21A ... First discharge passage, 21B ... Second discharge passage, 22A ... First suction valve element, 22B 2nd suction valve body, 23A ... 1st discharge passage, 23B ... 2nd discharge passage, 25 ... Lid body, 27 ... Suction space, 28 ... Communication passage, 29 ... Discharge space, 30 ... Suction port, 31 ... discharge port, 3 ... introduction passage, 36 ... housing, 37 ... drive chamber, 38 ... first sealing material, 39,45 ... second sealing material, 39a, 45a ... hole, 39b, 45b ... inner peripheral surface, 40 ... shaft seal portion .

Claims (2)

A rotating body to which the output shaft of the motor is fixed, a drive shaft projecting in a state inclined to a portion eccentric from the output shaft of the rotating body, a drive body rotatably supported by the drive shaft, A diaphragm in which each diaphragm portion forming a plurality of pump chambers is attached to the drive body, a suction passage for sucking fluid into the pump chamber, a suction valve body for opening and closing the suction passage, and a pump chamber A discharge passage for discharging fluid, a discharge valve body for opening and closing the discharge passage, and a communication passage for sequentially communicating the discharge passage and the suction passage between adjacent pump chambers among the plurality of pump chambers And following the rotation of the rotating body, the diaphragm portion of the diaphragm is reciprocated through the driving shaft and the driving body to expand and contract the pump chamber. In ear Fulham pump,
A housing that houses the diaphragm and the diaphragm form a sealed drive chamber,
A diaphragm pump, characterized in that an introduction passage is provided for introducing a part of the fluid passing through the communication passage into the drive chamber. The diaphragm pump according to claim 1, wherein
A sealing material formed of an elastic material is interposed between the motor and the housing;
A diaphragm pump characterized in that the seal material is provided with a hole whose inner peripheral surface is in close contact with the outer peripheral surface of the output shaft of the motor.

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