Pressure Regulator

Abstract

To provide a diaphragm pump capable of adjusting a pressure without using a creeping speed exhaust valve in an exhaust system.SOLUTION: A diaphragm pump includes: a diaphragm 31 having a cup-like pump portion 32; a pump chamber 34 applying the pump portion 32 as a part of a wall; and a driving mechanism 15 for increasing and decreasing a volume of the pump chamber 34. It further includes: a suction passage 49 connected to the pump chamber 34 at one end and connected to a fluid inlet 48 at the other end; and a suction valve 41 for opening and closing the suction passage 49. It further includes: a delivery passage 54 connected to the pump chamber 34 at one end and connected to a fluid delivery port 53 at the other end; and a delivery valve 42 for opening and closing the delivery passage 54. It furthermore includes a discharge passage 62 connected to the delivery passage 54 at one end and connected to a fluid discharge port 63 at the other end.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a diaphragm pump capable of adjusting the pressure of a discharged fluid, and a pressure adjusting device using this diaphragm pump. [Background technology]

[0002] Conventionally, as a pressure regulating device that uses air as a medium to pressurize or reduce the pressure of a pressurized object, there is one that supplies air to the cuff of an electronic blood pressure monitor, as described in Patent Document 1. The pressure regulating device disclosed in Patent Document 1 includes a pump that supplies air to the cuff of the electronic blood pressure monitor, and a slow exhaust valve that gradually exhausts the air stored in the cuff at a constant speed during blood pressure measurement.

[0003] An example of a pump capable of supplying air to the cuff of an electronic blood pressure monitor is a diaphragm pump as described in Patent Document 2. The diaphragm pump disclosed in Patent Document 2 is configured to convert the rotation of a motor into reciprocating motion and transmit it to a pump section of a diaphragm, and to discharge air drawn into the pump section during the stroke in which the pump section expands, during the stroke in which the pump section contracts. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-70969 A [Patent Document 2] JP 2018-112127 A Summary of the Invention [Problem to be solved by the invention]

[0005] The pressure regulating device described in Patent Document 1 uses a slow exhaust valve to regulate the pressure, which increases the number of parts and increases the manufacturing cost.

[0006] An object of the present invention is to provide a diaphragm pump and a pressure regulator capable of adjusting pressure without using a slow exhaust valve in the exhaust system. [Means for solving the problem]

[0007] In order to achieve this object, the diaphragm pump of the present invention includes a diaphragm having a cup-shaped pump portion, a pump chamber formed so that the pump portion forms part of the wall, a drive device connected to the bottom of the pump portion and converting rotation into reciprocating motion to increase or decrease the volume of the pump chamber, a suction passage having one end connected to the pump chamber and the other end connected to a fluid inlet outside the pump, a suction valve opening and closing the suction passage so that fluid flows from the fluid inlet to the pump chamber during a stroke in which the volume of the pump chamber increases, a discharge passage having one end connected to the pump chamber and the other end connected to a fluid outlet outside the pump, a discharge valve opening and closing the discharge passage so that fluid flows from the pump chamber to the fluid outlet port during a stroke in which the volume of the pump chamber decreases, and a discharge passage having one end connected to the discharge passage and the other end connected to a fluid discharge port outside the pump.

[0008] The pressure regulating device of the present invention comprises a motor that applies a rotational force to the drive device of the diaphragm pump, and a control device that controls the operation of the motor, and the control device is configured to adjust the pressure of the fluid discharged from the fluid discharge port by controlling the rotation speed of the motor.

[0009] The pressure regulating device of the present invention may further include a fluid passage that connects the discharge passage of the diaphragm pump with an object to be pressurized, and a discharge valve that selectively discharges fluid in the fluid passage. Effect of the Invention

[0010] According to the present invention, the pressure in the discharge passage of the diaphragm pump can be adjusted without using a slow exhaust valve in the discharge passage of the diaphragm pump by changing the rotation speed of the drive device of the diaphragm pump. Therefore, it is possible to provide a diaphragm pump and a pressure regulator that can adjust the pressure without using a slow exhaust valve in the exhaust system, thereby reducing costs. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a block diagram showing the configuration of a pressure regulating device according to the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of a diaphragm pump. [Diagram 3] FIG. 3 is a graph showing the relationship between the rotation speed of the motor and the discharge pressure of the diaphragm pump. [Figure 4] FIG. 4 is a graph showing the change in discharge pressure over time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] BEST MODE FOR CARRYING OUT THE DISCLOSURE Hereinafter, an embodiment of a diaphragm pump and a pressure regulating device according to the present invention will be described in detail with reference to Figs. The pressure adjusting device 1 shown in Fig. 1 can be used, for example, as a device for supplying air to a cuff A of an electronic blood pressure monitor (not shown). In this embodiment, the cuff A corresponds to the "object to be pressurized" according to the invention described in claim 3. The pressure adjusting device 1 includes a pump drive motor 2, a control device 3 for controlling the operation of the pump drive motor 2, and an operation switch 4, a pressure sensor 5, and a discharge valve 6 connected to the control device 3.

[0013] Pump drive motor 2 rotates when power is supplied from pump control section 7 of control device 3, and drives diaphragm pump 11, which will be described later. Diaphragm pump 11, which will be described in detail later, supplies air to cuff A of the electronic blood pressure monitor when driven by pump drive motor 2. Pressure sensor 5 detects the pressure in air passage B between diaphragm pump 11 and cuff A, and sends the detected pressure as a signal to control device 3. In this embodiment, air passage B corresponds to the "fluid passage" defined in claim 3.

[0014] The exhaust valve 6 is constituted by an electromagnetic valve, and selectively exhausts the air in the air passage B to the atmosphere. The operation of the exhaust valve 6 is controlled by an exhaust valve control unit 8 of the control device 3. The pump control unit 7 of the control device 3 controls the rotation speed of the pump drive motor 2 based on the pressure detected by the pressure sensor 5 . The discharge valve control section 8 of the control device 3 is configured to open the discharge valve 6 when discharging the residual pressure in the cuff A, and to close the discharge valve 6 at other times. The operation of the control device 3 will be described later. The operation switch 4 is a switch that is manually operated and is used to switch the control device 3 between ON and OFF.

[0015] As shown in FIG. 2, the diaphragm pump 11 is attached to the pump drive motor 2 which is located at the bottom in FIG. 2, and includes a drive unit 12 fixed to the pump drive motor 2, and a valve unit 13 attached to this drive unit 12.

[0016] <Drive unit configuration> The drive unit 12 is made up of a drive unit housing 14 fixed to the pump drive motor 2, and a drive mechanism 15 accommodated in this housing 14. The housing 14 is formed in a cylindrical shape with a bottom, and is fixed to the pump drive motor 2 by a fixing bolt (not shown). The drive mechanism 15 includes a crank body 17 attached to a rotary shaft 16 of the pump drive motor 2, and a drive body 19 connected to the crank body 17 via a drive shaft 18, etc.

[0017] The drive shaft 18 is inclined in a predetermined direction relative to the rotation shaft 16 . The driver 19 is composed of a cylindrical shaft portion 20 rotatably supported by the drive shaft 18, and a plurality of arms 21 protruding radially outward from the shaft portion 20. The arm portions 21 are provided for each pump portion 32 of a diaphragm 31 described later, and extend radially outward from the shaft portion 20 in the radial direction.

[0018] A through hole 21a is formed in the arm portion 21. A connecting piece 33 of the diaphragm 31 is fitted into this through hole 21a. The connecting piece 33 is fixed to the arm portion 21 in a state where it passes through the arm portion 21. According to this drive mechanism 15, a rotational force is applied from the rotating shaft 16 of the pump drive motor 2 to rotate the crank body 17 and the drive shaft 18, causing the drive body 19 to oscillate and the pump portion 32 of the diaphragm 31 to repeatedly contract and expand. In other words, the drive mechanism 15 converts the rotation of the crank body 17 into a reciprocating motion, and increases and decreases the volume of the pump chamber 34 in the pump portion 32. In this embodiment, the drive mechanism 15 corresponds to the "drive device" as defined in the present invention.

[0019] <Valve section configuration> The valve portion 13 includes a diaphragm 31 connected to the driver 19, a diaphragm holder 35 attached to the opening of the driver housing 14, a diaphragm housing 36 attached to the diaphragm holder 35 with the diaphragm 31 sandwiched between the diaphragm holder 35 and the cover 37 attached to the diaphragm housing 36. The diaphragm holder 35, the diaphragm housing 36 and the cover 37 are formed in a circular shape when viewed from the axial direction of the pump drive motor 2.

[0020] The diaphragm holder 35 is formed in a cylindrical shape that can be connected to the drive unit housing 14, and is formed with a plurality of cylinder holes 38 into which the pump portion 32 of the diaphragm 31, which will be described later, is inserted. The diaphragm 31 has a plurality of cup-shaped pump portions 32 that open toward the diaphragm housing 36 . The pump portions 32 are provided at positions that divide the diaphragm 31 into a plurality of portions in the circumferential direction of the cylindrical diaphragm holder 35. These pump portions 32 are inserted into cylinder holes 38 formed in the diaphragm holder 35.

[0021] The opening of the pump portion 32 is closed by a diaphragm housing 36. A pump chamber 34 is formed between the pump portion 32 and the diaphragm housing 36, with the pump portion 32 forming a part of the wall. A piston 39 is provided at the bottom of the cup-shaped pump section 32, and a connecting piece 33 is provided which protrudes in the opposite direction to the pump chamber 34. As described above, this connecting piece 33 is connected to the driver 19 of the drive mechanism 15. Therefore, when the driver 19 swings, the bottom (piston 39) of the pump section 32 moves toward and away from the diaphragm housing 36, causing the volume of the pump chamber 34 to increase or decrease.

[0022] The diaphragm housing 36 is formed in a disk shape, and supports a plurality of suction valves 41 on the outer periphery, and supports one discharge valve 42 in the center. An annular suction fluid chamber 43 is formed on the outer periphery between the diaphragm housing 36 and the cover 37. In addition, a discharge fluid chamber 45 separated from the suction fluid chamber 43 by a cylindrical wall 44 is formed on the center between the diaphragm housing 36 and the cover 37.

[0023] The suction fluid chamber 43 is connected to each of the multiple pump chambers 34 through a first through hole 46 provided in the diaphragm housing 36 for each pump chamber 34. The suction fluid chamber 43 is also connected to the atmosphere through a second through hole 47 formed in the cover 37. The second through hole 47 extends from a fluid inlet 48 formed on the outer surface of the cover 37, which is the outside of the pump, to the suction fluid chamber 43. In this embodiment, the first through hole 46 for each pump chamber 34, the suction fluid chamber 43, the second through hole 47, etc. form a suction passage 49 having one end connected to the pump chamber 34 and the other end connected to a fluid inlet 48 on the outside of the pump.

[0024] The suction valve 41 is for opening and closing the suction passage 49, and is formed of a rubber material into a predetermined shape. The suction valve 41 according to this embodiment has a shaft portion 41a that penetrates the diaphragm housing 36 and is fixed to the diaphragm housing 36, and a valve body 41b that is formed into a disk shape at the tip of the shaft portion 41a. The suction valve 41 is provided for each pump chamber 34 so that the valve body 41b is located in each pump chamber 34. The valve body 41b opens the opening portion of the first through hole 46 during a stroke in which the pump portion 32 of the diaphragm 31 expands and the volume of the pump chamber 34 increases, and closes the opening portion of the first through hole 46 during a stroke in which the pump portion 32 contracts and the volume of the pump chamber 34 decreases. That is, the suction valve 41 opens and closes the suction passage 49 so that the fluid flows from the fluid inlet 48 toward the pump chamber 34 during a stroke in which the volume of the pump chamber 34 increases.

[0025] Discharge fluid chamber 45 communicates with each of the multiple pump chambers 34 through third through holes 51 formed for each pump chamber 34 in diaphragm housing 36. Discharge fluid chamber 45 also communicates with the atmosphere through discharge pipe 52 formed in cover 37. Discharge pipe 52 is connected to, for example, cuff A of an electronic blood pressure monitor via an air hose (not shown) that constitutes air passage B. The hollow portion 52a of the discharge pipe 52 extends from a fluid discharge port 53 formed on the outer surface of the discharge pipe 52, which is outside the pump, to the discharge fluid chamber 45. In this embodiment, a discharge passage 54 is formed having one end connected to the pump chamber 34 and the other end connected to the fluid discharge port 53 outside the pump, by the third through hole 51 for each pump chamber 34, the discharge fluid chamber 45, the hollow portion 52a of the discharge pipe 52, etc. The pressure sensor 5 described above detects the pressure in the air passage B between the discharge passage 54 and the cuff A.

[0026] The discharge valve 42 is made of a rubber material and has a valve body 42a that is in close contact with the wall surface of the diaphragm housing 36 on the side of the discharge fluid chamber 45. The valve body 42a closes the opening of the third through hole 51 in an openable and closable manner, closing the opening of the third through hole 51 in a stroke in which the pump section 32 of the diaphragm 31 expands and the volume of the pump chamber 34 increases, and opening the opening of the third through hole 51 in a stroke in which the pump section 32 contracts and the volume of the pump chamber 34 decreases. In other words, the discharge valve 42 opens and closes the discharge passage 54 so that the fluid flows from the pump chamber 34 toward the fluid discharge port 53 in a stroke in which the volume of the pump chamber 34 decreases.

[0027] A discharge passage 62 consisting of a fourth through hole 61 is provided in a portion of the cover 37 covering the discharge fluid chamber 45. One end of the discharge passage 62 is connected to the discharge passage 54. The other end of the discharge passage 62 is connected to a fluid discharge port 63 formed in the outer surface of the cover 37, which is the outside of the pump.

[0028] <Explanation of operation> In the diaphragm pump 11 thus configured, when the pump portion 32 of the diaphragm 31 expands and the volume of the pump chamber 34 increases, the suction valve 41 opens and air is sucked into the pump chamber 34 through the suction passage 49. On the other hand, when the pump portion 32 of the diaphragm 31 contracts and the volume of the pump chamber 34 decreases, the discharge valve 42 opens and the air in the pump chamber 34 is discharged into the discharge fluid chamber 45 through the third through hole 51. Most of the air that has flowed into the discharge fluid chamber 45 is discharged from the fluid discharge port 53 through the hollow portion 52a (discharge passage 54) of the discharge pipe 52, and is sent to the cuff A through the air hose (air passage B).

[0029] A portion of the air that has flowed into the discharge fluid chamber 45 is discharged to the atmosphere through the discharge passage 62. By discharging a portion of the air from the discharge passage 62 in this manner, the discharge pressure of the air discharged from the fluid discharge port 53 can be easily adjusted by adjusting the balance between the discharge amount and the discharge volume by controlling the rotation speed of the motor 2. The rotation speed of the pump drive motor 2 is controlled by the pump control unit 7 of the control device 3. The discharge pressure of this diaphragm pump 11 changes in response to the rotation speed of the pump drive motor 2, as shown in FIG. 3.

[0030] When the pressure adjusting device 1 according to this embodiment is installed in an electronic blood pressure monitor, the pump control unit 7 of the control device 3 controls the rotation speed of the pump drive motor 2 so that the discharge pressure of the diaphragm pump 11 changes in a pattern suitable for blood pressure measurement. That is, as shown in FIG. 4, the pump control unit 7 increases the rotation speed of the pump drive motor 2 so that the pressure of the cuff A becomes a predetermined initial pressure P1, and then gradually reduces the rotation speed of the pump drive motor 2. When the rotation speed of the pump drive motor 2 decreases, the discharge pressure gradually decreases because air is constantly discharged from the discharge fluid chamber 45 through the discharge passage 62. In the electronic blood pressure monitor, blood pressure measurement is started when the discharge pressure decreases to P2 in the process in which the discharge pressure gradually decreases in this way. The pump control unit 7 stops the pump drive motor 2 when the discharge pressure reaches P3 after the blood pressure measurement is completed. When the pump drive motor 2 stops, the air in the discharge fluid chamber 45 is discharged from the discharge passage 62 to the atmosphere. In addition, when the discharge pressure reaches P3, the discharge valve 6 is controlled by the exhaust valve control unit 8 to open. When the exhaust valve 6 opens, the air in the air passage B is exhausted to the atmosphere, causing the cuff A to contract to its initial shape.

[0031] Therefore, according to this embodiment, by changing the rotation speed of drive mechanism 15 (drive device) of diaphragm pump 11, it is possible to adjust the pressure in discharge passage 54 of diaphragm pump 11 without using a slow exhaust valve in discharge passage 54 of diaphragm pump 11. Therefore, it is possible to provide a diaphragm pump and a pressure adjustment device that are capable of adjusting the pressure without using a slow exhaust valve, thereby reducing costs.

[0032] In the above-described embodiment, an example of using the present invention in an electronic blood pressure monitor has been shown, but the present invention is not limited to such a limitation and can be applied to any device that adjusts pressure by supplying and discharging gas or liquid. [Explanation of symbols]

[0033] 1...pressure regulating device, 2...pump drive motor, 6...discharge valve, 11...diaphragm pump, 15...drive mechanism (drive device), 31...diaphragm, 32...pump section, 34...pump chamber, 41...suction valve, 42...discharge valve, 48...fluid inlet, 49...suction passage, 53...fluid discharge port, 54...discharge passage, 62...discharge passage, 63...fluid discharge port.

Claims

1. A diaphragm having a cup-shaped pump portion; a pump chamber in which the pump portion is formed as a part of a wall; a drive device connected to a bottom of the pump section and converting rotation into reciprocating motion to increase or decrease the volume of the pump chamber; a suction passage having one end connected to the pump chamber and the other end connected to a fluid inlet on the outside of the pump; a suction valve that opens and closes the suction passage so that fluid flows from the fluid inlet toward the pump chamber during a stroke in which the volume of the pump chamber increases; a discharge passage having one end connected to the pump chamber and the other end connected to a fluid discharge port of a cover located outside the pump; a discharge valve that opens and closes the discharge passage so that fluid flows from the pump chamber toward the fluid discharge port during a stroke in which the volume of the pump chamber decreases; a motor for applying a rotational force to the drive device of a diaphragm pump having a discharge passage, the discharge passage having one end connected to the discharge passage and the other end connected to a fluid discharge port outside the pump, the discharge passage being formed of a through hole penetrating the cover and through which fluid is always discharged; A control device for controlling the operation of the motor, A pressurized object whose pressure is adjusted is connected to the fluid discharge port, The control device controls the rotation speed of the motor so that, while the motor is rotating, the discharge pressure of the diaphragm pump decreases without using a slow exhaust valve in the discharge passage and changes in a pattern suitable for adjusting the pressure of the object to be pressurized.

2. 2. The pressure regulating device according to claim 1, moreover, a fluid passage that communicates the discharge passage of the diaphragm pump with the object to be pressurized; and a drain valve that selectively drains the fluid in the fluid passage.

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