JP4465227B2 - Pump device - Google Patents

Description

  The present invention relates to a pump device for circulating a fluid. More specifically, the present invention relates to a pump device provided with a pump body using a diaphragm.

  As shown in FIG. 26, this type of circulation pump 100 includes a plurality of pump bodies 102 that suck and compress fluid by operation of the diaphragm 101, and the diaphragms 101 of the pump bodies 102 are arranged on the same plane. A known one is known (see JP-A-11-62837). The circulation pump 100 is rotatable by a motor 103 as a driving source, a rotating shaft 104 that is rotated by the motor 103 and has an end surface slightly inclined with respect to the rotation center, and an inclined peripheral surface of the rotating shaft 104. And a diaphragm 101 arranged at equal intervals around the cam plate 105.

  When the motor 103 is continuously driven to rotate the rotating shaft 104, the peripheral portion of the cam plate 105 is displaced in the axial direction of the rotating shaft 104 by the inclined end surface. The diaphragms 101 are moved in and out by the displacement of the cam plate 105 in the axial direction. When the diaphragm 101 is pressed, the volume of the pressure chamber 106 changes, and the fluid is sent in one direction by the action of the inflow valve and the outflow valve.

JP-A-11-62837

  However, in the circulating pump 100 described above, the diaphragm 101 is disposed on the same plane, so that it is difficult to reduce the size while maintaining the size of the pump body 102. In addition, since the diaphragm 101 is arranged on the same plane, if the diaphragm 101 is to be enlarged in order to increase the flow rate, the diameter of the cam plate 105 must be enlarged and the change becomes large.

  Further, since the cam plate 105 is slightly inclined with respect to the arrangement surface of the diaphragm 101 and the motor 103 continuously rotates, it is not possible to operate only one arbitrary pump body 102 independently. Have difficulty. That is, since the cam plate 105 is slightly inclined with respect to the arrangement surface of the diaphragm 101, the adjacent pump bodies 102 always operate. Therefore, it is difficult to operate only one pump body 102 to obtain a minute flow rate.

  Accordingly, an object of the present invention is to provide a pump device that can be easily miniaturized and obtain a minute flow rate.

To achieve the above object, the pumping device according to claim 1, a stepping motor, and an eccentric member mounted eccentrically on the output shaft of the stepping motor, in the radial direction of the output shaft and engaged with the eccentric member A cam mechanism for converting into motion, and a plurality of pump bodies arranged at equal intervals around the cam mechanism, and having a diaphragm that pumps by moving in and out in the radial direction of the output shaft by operating the cam mechanism ; The cam mechanism operates only one pump body among the plurality of pump bodies so as not to come into contact with other diaphragms in a state where any one of the diaphragms of the plurality of pump bodies is operated. Yes.

  Therefore, when the motor is driven, the eccentric member rotates and presses the diaphragm via the cam mechanism to operate the pump body. As a result, the pump device operates to suck or compress the fluid.

Further, since the so that using the scan stepping motor, Ki out to control the cam mechanism at small angles, it is possible to obtain a very small flow rate by operating only one pump body.

  As described above, according to the pump device of the first aspect, since the cam mechanism displaces the diaphragm in the radial direction of the output shaft, there is no need to arrange the diaphragm on the same plane as in the prior art. The size of the apparatus can be reduced relatively easily.

Further, Runode have to use a scan stepping motor, can be controlled in a very small angle of the cam mechanism, it is possible to obtain a very small flow rate by operating only one pump body. Therefore, the applicable range of the pump device can be expanded.

  Hereinafter, the configuration of the present invention will be described in detail based on the best mode shown in the drawings.

  1 to 15 show an example of an embodiment of the pump device 1 of the present invention. As shown in FIG. 1, the pump device 1 includes a motor 2, an eccentric member 4 that is eccentrically attached to the output shaft 3 of the motor 2, and an engagement with the eccentric member 4 in the radial direction of the output shaft 3. A cam mechanism 5 for converting into motion is provided, and pump bodies 7 to 10 having a diaphragm 6 that appears and disappears in the radial direction of the output shaft 3 to perform a pump action when the cam mechanism 5 operates.

  The motor 2 is a stepping motor. The motor 2 is attached to the support plate 11 by screws. An inner ring 22 of a ball bearing 12 is attached to the eccentric member 4 by press-fitting, for example. A washer for holding the ball bearing 12 and a slit ring 13 are screwed to the tip of the output shaft 3 of the motor 2 with screws 14. The eccentric member 4 is fixed to the output shaft 3 of the motor 2 with screws 49.

  As shown in FIG. 2, the cam mechanism 5 includes a slide guide 15 formed integrally with the support plate 11, a slider 16 slidable in a direction perpendicular to the axial direction (radial direction), and a bearing holder that houses the ball bearing 12. 17. The slide guide 15 is formed in an annular shape centering on the output shaft 3 so as to protrude to the opposite side of the surface of the support plate 11 to which the motor 2 is attached. The end face has at least two guide grooves 18 formed in the radial direction.

  The slider 16 has an annular shape, and is formed in a radial direction in which the slide guide side convex portion 19 that protrudes in the radial direction that protrudes toward the slide guide 15 and the slide guide side convex portion 19 that protrudes in the radial direction at a different angle. The bearing holder side convex part 20 was provided. The bearing holder 17 has a cylindrical shape, and has a guide groove 21 formed in a radial direction in which the bearing holder side convex portion 20 is slidably engaged on the end surface on the slider 16 side. An outer ring 23 of the ball bearing 12 is fitted to the bearing holder 17.

  As shown in FIG. 3, a contact ring 24 is rotatably attached to the outer peripheral portion of the bearing holder 17. Since the contact ring 24 can rotate with respect to the bearing holder 17, as shown in FIG. 4, when the contact ring 24 comes into contact with the diaphragm 6, the contact ring 24 rotates with respect to the bearing holder 17 to reduce an impact at the time of contact. be able to. A concave groove 25 is formed on the outer peripheral surface to which the contact ring 24 of the bearing holder 17 is fitted, and a convex portion 26 to be fitted to the concave groove 25 is formed on the inner peripheral surface of the contact ring 24. . When the concave groove 25 and the convex portion 26 are engaged by snap fitting, the contact ring 24 can be rotated and can be easily assembled with one touch.

  Each of the pump bodies 7 to 10 has the same configuration, and includes a pressure chamber 28 formed in the case 27 and a diaphragm 6 provided to close the pressure chamber 28 as shown in FIGS. 5 and 6. ing. These materials do not react with the carrier fluid or the circulating fluid. An annular groove 29 is formed around the opening edge of the pressure chamber 28. An annular bead 30 is formed on the diaphragm 6. When the bead 30 is pushed into the annular groove 29, the diaphragm 6 is fixed to the case 27 and the opening of the pressure chamber 28 can be sealed with the diaphragm 6. A planar seal portion 31 is continuously provided on the outer side of the bead 30 of the diaphragm 6. The seal portion 31 is sandwiched between the case 27 and the lid 32 and screwed, whereby the diaphragm 6 can be fixed and the pressure chamber 28 can be more firmly sealed. The displacement amount of the diaphragm 6 is set to be equal to or smaller than the eccentric amount of the eccentric member 4. However, the displacement amount of the diaphragm 6 can be changed by changing the eccentric amount of the eccentric member 4.

  A protrusion 33 for pressing and deforming the diaphragm 6 is formed at the center of the surface of the diaphragm 6 opposite to the pressure chamber 28. It is preferable to apply a fluorine coating to the projection 33 of the diaphragm 6 to increase durability and reduce contact resistance. Alternatively, the protrusion 33 may be covered with a material having wear resistance and a low friction coefficient so as to improve durability and decrease contact resistance.

  An inflow passage 34 and an outflow passage 35 communicating with the outside are formed in the pressure chamber 28. An L-shaped inflow valve groove 36 is formed in the middle of the inflow path 34, and an L-shaped inflow valve 37 is inserted and fixed in the inflow valve groove 36. The inflow valve 37 has a mounting portion 37a and a valve portion 37b. The valve portion 37 b is in close contact with the surface of the inflow valve groove 36 opposite to the pressure chamber 28. As a result, when the diaphragm is pushed and the pressure in the volume chamber increases, when the fluid flows out of the pressure chamber 28, the valve portion 37b comes into close contact with the wall of the inflow valve groove 36 and the flow is stopped, and the diaphragm returns. When the pressure decreases, when the fluid flows into the pressure chamber 28, the valve portion 37b moves away from the wall of the inflow valve groove 36 and the fluid flows. A so-called check valve is formed. A counterbore 39 for incorporating an O-ring 38 is formed at the inlet of the inflow passage 34.

  An L-shaped outflow valve groove 40 is formed in the middle of the outflow path 35, and an L-shaped outflow valve 41 is inserted and fixed in the outflow valve groove 40. The outflow valve 41 has a mounting portion 41a and a valve portion 41b. The valve portion 41b is in close contact with the surface of the outflow valve groove 40 on the pressure chamber 28 side. As a result, when the diaphragm returns and the pressure in the volume chamber decreases, when the fluid flows into the pressure chamber 28, the valve portion 41b is brought into close contact with the wall of the outflow valve groove 40 and the flow is stopped, and the diaphragm is pushed and the volume chamber is pressed. When the fluid pressure increases, when the fluid flows out from the pressure chamber 28, the valve portion 41 b moves away from the wall of the outflow valve groove 40 and the fluid flows. A so-called check valve is formed. An outlet pipe 42 is provided at the outlet of the outlet path 35.

  Further, each of the valve portions 37b and 41b of the inflow valve 37 and the outflow valve 41 is made of an extremely thin elastic member so as to be deformed with a slight prescribed pressure. For this reason, the valve can be operated with a small pressure load. Furthermore, since the check valve structure that can be installed simply by being inserted into the valve grooves 36 and 40 is used in this way, it is possible to obtain a valve that is easy to assemble and has high sensitivity and high reliability, and can be used for a minute flow rate. .

  As shown in FIGS. 7 and 8, the lid 32 has convex portions 51 (indicated by a two-dot chain line in FIG. 7) at portions and positions surrounding the inflow valve groove 36, the outflow valve groove 40 and the annular groove 29 shown in FIG. Show). Due to the presence of the convex portion 51, the inflow valve groove 36, the outflow valve groove 40, and the annular groove 29 can be sealed through the plate-like seal portions 31.

  As shown in FIGS. 9 to 11, four pump bodies 7 to 10 are arranged around the cam mechanism 5. The projection 33 of the diaphragm 6 of each pump body 7 to 10 faces the contact ring 24 of the cam mechanism 5. In this embodiment, the pump bodies 7 to 10 are arranged at equal intervals every 90 degrees with the cam mechanism 5 as the center. Further, the relationship between the pump bodies 7 to 10 and the cam mechanism 5 is such that the two pump bodies 7 to 10 are not operated simultaneously as shown in FIGS. Thereby, since only one pump body 7-10 can be operated, the output of a very small flow rate can be obtained.

  The outflow pipes 42 of the pump bodies 7 to 10 are penetrated through the through holes of the support plate 11 of the cam mechanism 5. An O-ring 38 is incorporated in a counterbore 39 at the inlet of each inflow channel 34. Further, a flow path lid 43 is provided on the side surface of each pump body 7 to 10 opposite to the cam mechanism 5. As shown in FIG. 12, the flow path lid 43 includes a hole 44 provided at a position that matches the counterbore 39 of each pump body 7 to 10, and a pipe line 45 penetrating from the hole 44 to the side surface. The pipe 45 protrudes from the side surface of the flow path lid 43 to form a pipe shape and is configured to easily connect a pipe or the like.

  As shown in FIG. 1, a substrate 46 is provided on the inner surface side of the flow path lid 43. The substrate 46 is provided with a photo interrupter 47 for reading the rotation of the slit ring 13 attached to the output shaft 3 and its drive circuit. Thereby, the rotational position of the output shaft 3 can be detected. The slit ring 13 has a bowl shape having a flange portion passing between the light emitting element and the light receiving element of the photo interrupter 47, and a slit for detection is formed in the flange portion.

  The operation of the pump device 1 described above will be described below.

  When the motor 2 is driven, the inner ring 22 of the ball bearing 12 is rotated via the eccentric member 4. The outer ring 23 of the ball bearing 12 performs a turning motion with the eccentric amount of the eccentric member 4 as a radius. Therefore, the bearing holder 17 and the contact ring 24 also perform a turning motion with the eccentric amount of the eccentric member 4 as a radius. Here, since the cam mechanism 5 is operated to the output shaft 3 via the eccentric member 4, the contact ring 24 is rotated with the eccentric amount of the output shaft as a radius, and the contact point is separated from the center. Regardless, the contact speed V to the diaphragm is much smaller than when the rigid cam is attached to the rotating shaft. Therefore, since the contact PV (product of the pressure P and the speed V) can be made extremely small as compared with the case where the cam mechanism 5 is directly provided on the output shaft 3, the durability can be improved.

  When the motor 2 rotates, as shown in FIG. 13, the contact ring 24 sequentially presses and releases the projections 33 of the diaphragms 6 of the pump bodies 7 to 10. In each pump body 7 to 10, when the diaphragm 6 is pressed, the volume of the pressure chamber 28 is reduced and the inflow valve 37 is closed, and at the same time, the outflow valve 41 is opened. Thereby, the fluid is pushed out from the pressure chamber 28. Further, when the diaphragm 6 is released, the volume of the pressure chamber 28 is increased and the outflow valve 41 is closed, and at the same time, the inflow valve 37 is opened. As a result, the fluid is drawn into the pressure chamber 28. By repeating this, the fluid flows.

  The rotational position of the output shaft 3 is detected by a photo interrupter 47. Since the motor 2 is the stepping motor 2, the output shaft 3 can be rotated at an arbitrary angle with respect to each pump body 7-10. Moreover, the movement of the diaphragm 6 in each pump body 7-10 does not occur simultaneously by two pump bodies as shown by the solid line in FIG. Therefore, only any one pump body can be operated. In this case, the output shaft 3 is reciprocally rotated by 90 degrees as shown in FIG. Thereby, since the eccentric member 4 reciprocates every 90 degrees, only the target pump body can be operated. At this time, the diaphragms 6 of the other three pump bodies do not operate because they do not contact the contact ring 24. For example, in the example shown in FIG. 15, the pump body 7 is operated three times, then the pump body 8 is operated once, and the pump body 9 is further operated six times.

  As described above, since the motor 2 is a stepping motor, the forward and reverse rotation is easy, the controllability is high, the flow rate accuracy of the fluid can be increased, and the user-friendly pump device 1 can be obtained. Moreover, since the motor 2 is a stepping motor, it can be stopped when the operation is unnecessary, and an energy saving pump can be realized.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, in the present embodiment, the diaphragm 6, the inflow valve 37, and the outflow valve 41 are formed separately. However, the present invention is not limited to this, and these may be integrally formed as shown in FIGS. good. For example, in the illustrated example, the outflow valve 41 and the inflow valve 37 are integrally formed by cutting the diaphragm 6 into a U shape. In this embodiment, when the contact ring 24 is released, the diaphragm 6 returns to its original state. However, the present invention is not limited to this, and a return spring 48 is provided as shown in FIGS. You may do it. When the return spring 48 shown in FIG. 18 is used, the return spring 48 is made of a material that is not eroded by the fluid because it contacts the fluid.

  Furthermore, in the present embodiment, the assembly of the pump bodies 7 to 10 and the assembly of the pump bodies 7 to 10 and the support plate 11 are made by screwing. However, the invention is not limited to this, but by ultrasonic welding or adhesion. It is good as a thing. In this embodiment, the photo interrupter 47 is used to detect the rotation speed of the output shaft 3, but the present invention is not limited to this, and a known rotation detecting means such as a Hall element or MR element may be used. good.

  In the present embodiment, four pump bodies 7 to 10 are provided. However, the number of pump bodies 7 to 10 is not limited to this. For example, as shown in FIG. In this case, a smaller amount can secure a sufficient amount of displacement of the diaphragm 6. Furthermore, in this embodiment, the arrangement of the pump bodies 7 to 10 is only one stage in the axial direction of the output shaft 3. However, the arrangement is not limited to this, and a plurality of stages may be provided.

  In the present embodiment, the cam mechanism 5 is provided with the two free rotation members of the ball bearing 12 and the contact ring 24. However, the present invention is not limited to this, and the cam mechanism 5 may not be provided with the free rotation member. For example, it is good also as the cam mechanism 5 which consists of a cam member as shown in FIG. Further, a cam mechanism in which the roller 60 is eccentric from the output shaft 3 of the motor 2 and is rotatably attached to the roller holder 61 as shown in FIG.

  Furthermore, in this embodiment, the bearing holder 17 presses the diaphragm 6 via the contact ring 24 by the combination of the slide guide 15, the slider 16, and the bearing holder 17, but the present invention is not limited to this, and is shown in FIGS. Thus, instead of the slide guide 15, slider 16 and bearing holder 17, the diaphragm 6 is sequentially displaced by a pair of sliders 50 </ b> A and 50 </ b> B that reciprocate linearly around the ball bearing 12 in the eccentric direction of the eccentric member 4. You may make it perform a pump action. In this case, the sliders 50 </ b> A and 50 </ b> B are engaged with the outer races of the ball bearings 12 by engaging the central holes 54 in the radial direction, and the recesses 52 arranged on one of the two axes orthogonal to each other are placed in the center of the diaphragm 6. The head of the engaging piece 53 provided is engaged. The engaging pieces 53 are engaged so that their heads are fitted into the recesses 52 of the slider 50 </ b> A or 50 </ b> B and their necks are hooked on the flange 55. Thus, when the sliders 50A and 50B are alternately moved in directions orthogonal to each other by the eccentric rotation of the eccentric member 4, the pressure chamber 28 is contracted or expanded by pulling or pushing the diaphragm 6 through the engagement pieces 53. I have to. Here, each of the sliders 50A and 50B includes two linear grooves formed and arranged on the fixing member side so as to be orthogonal to each other, and plate-like protrusions fitted to the linear grooves, for example, a groove 57 provided on the support lid 11 and By engaging the projection 56 with a groove (not shown) provided in the flow path lid 43, the groove is supported so as to be slidable only in the radial directions perpendicular to each other. Thereby, when the motor 2 rotates, the sliders 50A and 50B engaged with the ball bearings 12 move along the groove 57 by the eccentric movement of the eccentric member 4, and push and pull the diaphragm 6 to function as a pump. Note that the engaging piece 53 such as a knob of the pot lid is attached so that the diaphragm 6 is sandwiched between the receiving plates 58 and fixed with screws 59.

  Moreover, although the diaphragm 6 is used in this embodiment, it is not restricted to this, You may use a tube.

It is a figure which shows the pump apparatus of this invention, (A) is a front view of the state which removed the flow path cover, (B) is a center longitudinal cross-sectional view. It is a disassembled perspective view which shows a cam mechanism. It is a disassembled perspective view which shows a bearing holder and a contact ring. It is a front view which shows the contact state of a contact ring and a diaphragm. It is a top view which shows the case of a pump body. It is a center longitudinal cross-section side view which shows a pump body. It is a bottom view which shows the cover of a pump body. It is a front view which shows the state cut | disconnected by VIII-VIII of FIG. It is a side view which shows a pump apparatus. It is a rear view which shows a pump apparatus. It is a front view which shows a pump apparatus. It is sectional drawing which shows a flow-path cover. It is a figure which shows the relationship with the diaphragm at the time of a cam mechanism rotating 180 degree | times. It is a figure which shows the relationship between the displacement amount of the diaphragm of each pump body, and the rotation angle of a cam mechanism. It is a figure which shows an example of the operation | movement which operates each pump body one by one. It is a top view which shows the pump body of other embodiment. It is a center longitudinal cross-section side view which shows the pump body of other embodiment. It is a longitudinal cross-sectional side view which shows the diaphragm of another embodiment. It is sectional drawing which shows the diaphragm of another embodiment. It is a top view of the embodiment which changed the number of pump bodies, (A) is provided with one unit, (B) is provided with two units, and (C) is provided with three pump units. It is a figure which shows the cam mechanism of other embodiment, (A) is a front view, (B) is a side view. It is a cross-sectional view which shows other embodiment of the pump apparatus of this invention. It is a longitudinal cross-sectional view of the pump apparatus. It is a disassembled perspective view of the pump apparatus. It is a perspective view which shows the cam mechanism of other embodiment. It is a center longitudinal cross-section side view which shows the conventional pump apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pump apparatus 2 Motor 3 Output shaft 4 Eccentric member 5 Cam mechanism 6 Diaphragm 7-10 Pump body

Claims (1)

A stepping motor, an eccentric member that is eccentrically attached to the output shaft of the stepping motor, a cam mechanism that engages with the eccentric member and converts it into a radial motion of the output shaft, and the cam mechanism operates. And a plurality of pump bodies arranged at equal intervals around the cam mechanism, and having a diaphragm that performs a pumping action by appearing in the radial direction of the output shaft. A pump apparatus characterized in that only one pump body among the plurality of pump bodies is operated so as not to come into contact with other diaphragms in a state where any one of the diaphragms is operated.

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