JP2009007980A - Liquid discharge device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid discharge device using an elastic body such as a diaphragm or a tube for reducing an error of a discharge amount while easily preventing the permanent deformation of the elastic body. <P>SOLUTION: The liquid discharge device comprises a case, a drive mechanism body provided in the case, and the diaphragm 8 mounted on the case. The drive mechanism body consists of a plurality of thrusting rods 33-35 provided movable in a first direction of approaching the diaphragm 8 and in a second direction of leaving the diaphragm 8, a disc spring 57 for energizing the thrusting rods 33-35 in the first direction, a driving means for individually moving the thrusting rods 33-35 in the second direction against the energizing force of the disc spring 57, and an energizing force cancelling means for cancelling the energizing force of the disc spring 57. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid discharge apparatus using a diaphragm or a tube, and can be used particularly for a diaphragm pump or a tube pump that transfers a predetermined amount of liquid.

Diaphragm pumps and tube pumps that use diaphragms and tubes can be made of synthetic resin for the diaphragms and tubes, so that liquids containing various fillers can be discharged without damaging the liquid to be sent. There is no need to use a sealing material for prevention, and there is an advantage that a structure in which the liquid does not touch the metal is possible.
In such a pump, a plurality of pressure rods are sequentially reciprocated with respect to the diaphragm or tube to press the diaphragm or tube, or release the pressure to repeat liquid suction, metering, and discharge operations. Is being discharged. The drive using the air cylinder is known for driving the pressure rod. However, the present applicant uses a cam that is rotated by a motor that can be driven at a higher speed than the air cylinder drive. It was developed (see Patent Document 1).

JP 2006-29314 A

By the way, in the diaphragm pump of the said patent document 1, since the disc spring which always urges | biases a press member to the diaphragm side was provided, there existed the following subjects.
That is, since the tip of the pressing member protrudes from the guide block, the diaphragm could not be set flat when setting the diaphragm between the guide block and the base block arranged to face the guide block. . That is, when the diaphragm is set, the portion of the diaphragm where the tip of the pressing member abuts is set in a deformed state. For this reason, there has been a problem that a periodic discharge amount error becomes large in the diaphragm pump.

In addition, since the pressing member is always urged toward the diaphragm side, the diaphragm is in a state where the portion pressed by the pressing member is always deformed, and the diaphragm does not return to the original state, that is, permanent deformation. There was also a problem.
Such a problem is not limited to a liquid discharge device (pump) using a diaphragm, but also applies to a liquid discharge device such as a tube pump using a tube instead of a diaphragm.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid ejection apparatus that can reduce an error in ejection amount and can easily prevent permanent deformation of an elastic body in a liquid ejection apparatus that uses an elastic body such as a diaphragm or a tube. .

  A liquid discharge apparatus according to the present invention is a liquid discharge apparatus including a case, a drive device main body provided in the case, and an elastic body attached to the case, and the elastic body is a diaphragm or a tube. The drive device body includes a plurality of pressing members movably provided in a first direction approaching the elastic body and a second direction away from the elastic body, and biases each pressing member in the first direction. The pressing member urging means, the driving means for individually moving the pressing members in the second direction against the urging force of the pressing member urging means, and the urging force by the pressing member urging means. Biasing force releasing means for releasing.

In the present invention, the plurality of pressing members are moved by the urging force of the pressing member urging means in the first direction approaching the elastic body, and are moved by the driving means in the second direction away from the elastic body. That is, each pressing member is reciprocated by the pressing member urging means and the driving means.
Here, when the pressing member moves in the first direction, the elastic body is pressed. For this reason, the liquid flow path formed between the mounting surfaces to which the diaphragm and the diaphragm are mounted and the liquid flow path formed in the hollow tube are closed.
On the other hand, when the pressing member that has pressed the elastic body moves in the second direction, the pressing is released and the elastic body returns to the original state. For this reason, the liquid channel returns from the closed state to the open state.
Therefore, by sequentially pressing the elastic body with a plurality of pressing members or releasing the pressing, liquid can be discharged sequentially like a diaphragm pump or a tube pump.

Further, when the urging force of the pressing member urging means is released by the urging force releasing means, the urging force of the elastic body by the pressing member is released, so that the pressing member does not protrude from the guide block that guides the pressing member. It becomes possible. For this reason, when the elastic body is set in the liquid ejection device, it is possible to prevent the pressing member from protruding from the guide block or the like. When the diaphragm is used as the elastic body, the entire diaphragm can be set flat, and the diaphragm It is possible to reduce an error in the discharge amount that occurs because a part is set by being deformed. Similarly, when a tube is used as the elastic body, a part of the tube is not deformed and set, and an error in the discharge amount caused by the deformation can be reduced.
Furthermore, when the liquid ejection device is stopped, the urging force releasing means can release the urging force of the pressing member, so that the elastic body can be prevented from being always urged by the pressing member, and the elastic body can be permanently deformed Can be reduced. For this reason, the period until the elastic body is replaced can be extended, and the replacement cost can be reduced.

  In the liquid ejection apparatus of the present invention, a guide block that guides each pressing member is provided in the case, and the drive means is in the direction of the rotation axis with respect to the rotation drive source and the output shaft of the rotation drive source. A cam that is movable and rotatable integrally with the output shaft, and a contact member that is disposed in the guide block and that urges each pressing member in the second direction to contact the cam surface of the cam. The urging force releasing means is arranged on the second direction side of the cam and is slidable within a predetermined range along the first direction and the second direction. The pressing member biasing means is constituted by a spring disposed between the cam and the spring receiving member, and the spring receiving member is located at a stroke end position on the first direction side. In the state moved to The pressing member is urged in the first direction by the pressing member urging means, and in a state where the spring receiving member is moved to the stroke end position on the second direction side, the pressing member is urged by the pressing member urging means. It is preferable that the urging force is released, and the urging means for urging is urged in the second direction so that the end of the pressing member on the first direction side is moved to a position where it does not protrude from the guide block. .

  According to such a configuration, it is possible to easily switch between a state in which the urging force is applied to the pressing member and a state in which the urging force of the pressing member is released by simply sliding the spring receiving member.

In the liquid ejection apparatus according to the aspect of the invention, it is preferable that the elastic body is formed of a diaphragm, and the guide block is urged in a first direction by a guide block urging unit and is in close contact with the diaphragm.
According to such a configuration, since the guide block urging means is provided, the guide block can be securely brought into close contact with the diaphragm.

  The liquid ejection apparatus of the present invention comprises a flow path block, a diaphragm provided in close contact with the flow path block, and drive means for reciprocatingly driving the diaphragm, and is defined by the flow path block and the diaphragm. In addition, at least three or more liquid flow paths communicating with the liquid suction flow path and the discharge flow path are provided, and the flow path block is connected to the central flow path portion of the diaphragm contact surface to which the diaphragm is in close contact. One of the discharge channels is formed, the other of the suction channel or the discharge channel is formed on the outer peripheral side of the diaphragm contact surface, and the suction side valve communicated with the suction channel in the middle of each liquid channel A discharge side valve chamber communicated with the discharge flow path, and a measurement chamber formed between the suction side valve chamber and the discharge side valve chamber and communicated with each valve chamber. The drive means is provided with a suction side pressing member provided corresponding to the suction side valve chamber, with the diaphragm interposed between the suction side valve chamber and the diaphragm on the discharge side valve chamber. A discharge-side pressing member provided corresponding to the discharge-side valve chamber, and a measuring chamber pressing member provided corresponding to the measuring chamber, with a diaphragm interposed between the measuring chamber and the discharge-side pressing member. A drive device main body that controls the driving of each pressing member, and the drive device main body includes a rotation drive source, a cam that is rotated by the rotation drive source, and each pressing member that is connected to the cam. A contact urging means for abutting on the cam surface; and a pressing member urging means for urging each pressing member in the first direction, and the suction side pressing member is moved in the first direction to form a diaphragm. Inhalation side valve The suction side valve sealing operation for closing the suction side valve chamber by moving the portion corresponding to the chamber until it closely contacts the flow path block, and moving the discharge side pressing member in the first direction to correspond to the discharge side valve chamber of the diaphragm The discharge side valve sealing operation for moving the portion to be in close contact with the flow path block to seal the discharge side valve chamber, the suction of the diaphragm being in close contact with the flow path block by moving the suction side pressing member in the second direction A suction side valve opening operation for opening the suction side valve chamber by separating a part corresponding to the side valve chamber from the flow path block, and a diaphragm in which the discharge side pressing member is moved in the second direction and is in close contact with the flow path block The portion corresponding to the discharge side valve chamber is moved away from the flow path block to release the discharge side valve chamber, and the metering chamber pressing member is moved in the first direction. A volume reducing operation for gradually reducing the volume in the measuring chamber by bringing the portion corresponding to the measuring chamber of the diaphragm closer to the flow path block, and the pressing member for the measuring chamber is moved in the second direction to correspond to the measuring chamber of the diaphragm The volume increasing operation for gradually increasing the volume of the measuring chamber by moving the portion to be away from the flow path block, by rotating the cam with a rotational drive source and reciprocally driving each pressing member following the cam surface, It may be executed at a predetermined timing set for each pressing member.

In the present invention as described above, each valve chamber provided in each liquid flow path is reciprocated at a predetermined timing to open and close each valve chamber or the volume of the measurement chamber. Can be increased or decreased. For this reason, by moving each pressing member at a predetermined timing, backflow can be prevented without using a check valve, and the liquid can be transferred. Therefore, since the check valve is not provided, the liquid can be made to flow backward by reversing the driving of each pressing member.
Further, three or more liquid flow paths are formed, each of the liquid flow paths is provided with the respective valve chambers and measuring chambers, and a pressing member corresponding to each of the valve chambers and the measuring chambers is provided for each liquid flow path. Since the liquid transfer timing can be set, by shifting the liquid transfer timing for each liquid channel by a predetermined phase, a certain amount of liquid can be continuously transferred, and a pump with less pulsation can be obtained.
Furthermore, the present invention does not drive the entire diaphragm forward and backward as in the case of a conventional diaphragm pump, but instead drives the portions corresponding to the valve chambers and the metering chambers individually in one diaphragm. Only a very narrow area needs to be driven compared to the whole, and the error of the liquid transfer amount due to deformation of the diaphragm itself can be reduced. For this reason, even if the liquid transfer amount is very small, it can be transferred accurately.
In addition, by providing the diaphragm, the drive means side such as the pressing member can be partitioned from the liquid flow side such as the liquid flow path, the valve chamber, and the measurement chamber. Therefore, there is no need to provide a sealing material, and the number of parts can be reduced accordingly.
In addition, since the diaphragm is made of elastically deformable rubber or the like, even a liquid containing particles such as silver paste, solder paste, and resin mixed with silica powder can be discharged without crushing the particles. Can be transported without causing damage.
Further, in the present invention, one of the suction flow path or the discharge flow path is formed in the central axis portion of the diaphragm contact surface, and the other of the suction flow path or the discharge flow channel is formed on the outer peripheral side of the diaphragm contact surface. Three or more fluid flow paths communicating between the suction flow path and the discharge flow path can be formed radially or spirally from the central axis portion toward the outer periphery. Furthermore, each pressing member provided corresponding to each fluid flow path is driven to reciprocate following the cam surface only by rotating the cam by a rotational drive source. For this reason, the drive device main body includes a cam having a cam surface on the end surface, a rotational drive source such as a motor that rotates the cam, and a contact biasing means such as a spring that causes each pressing member to contact the cam surface. The pressing member urging means for urging each pressing member in the first direction can be configured, and the diaphragm pump can be reduced in size and weight. Therefore, when using the diaphragm pump of the present invention for discharging adhesives and various pastes in the production line of various products, it can be attached to the robot arm and moved at high speed and high acceleration. The tact time can be shortened, and it can contribute to productivity improvement.
Furthermore, in the present invention, each pressing member can be repeatedly operated at a predetermined timing by simply rotating the cam with a rotational drive source such as a motor. At this time, since the liquid transfer amount for each cycle operation of each pressing member can be set to be constant, the liquid transfer amount per unit time can be adjusted only by adjusting the rotational speed of the cam. Therefore, the liquid transfer amount in the diaphragm pump can be controlled very easily, and an easy-to-use diaphragm pump (dispenser) can be realized.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
1 and 2 show a diaphragm pump 1 according to a first embodiment of the present invention.
The diaphragm pump 1 includes a suction block 2, a pump block 3, a holding block 4, a motor mounting block 5, and a drive unit 6. The case of the diaphragm pump 1 is comprised by each block 2-5.

As shown in FIG. 3, the suction block 2 is formed in a substantially circular plane, and is detachably attached to the pump block 3 by screws 10 that are screwed into the pump block 3 through four through holes 21 around the suction block 2. .
The pump block 3 and the holding block 4 are detachably attached to each other by screws (not shown) screwed into the pump block 3 from the holding block 4 side.

Further, as shown in FIG. 2, the holding block 4 and the motor mounting block 5 are attached by screws 11 screwed from the motor mounting block 5 side.
Further, a retaining screw 12 is screwed into the holding block 4 through the motor mounting block 5.
Each of the screws 11 and 12 is provided in two, and each of the screws 11 and 12 is provided in a substantially diagonal position in the planar position of each of the blocks 4 and 5.
Each of these blocks 3, 4, 5 is formed with a through hole in the central shaft portion, and a guide member 30, a cam 51, and the like which will be described later are disposed.

An annular (ring-shaped) diaphragm locking groove 22 is formed on the surface (upper surface) of the suction block 2 facing the pump block 3 as shown in FIG.
An arcuate suction channel 23 is formed on the inner peripheral side of the diaphragm locking groove 22. A port 24 serving as a liquid supply hole is formed between the side surfaces of the suction channel 23 and the suction block 2 so as to penetrate therethrough.
A joint 13 is attached to the side surface of the suction block 2 with a cap nut 14, and the port 24 communicates with the joint 13. An unillustrated syringe or tube is attached to the joint 13 and supplied with a liquid for discharge.

On the upper surface of the suction block 2, a plurality of mounting holes 25 are formed inside the suction flow path 23.
Further, a through-hole 26 that continues to the lower surface of the suction block 2 is formed in the central axis portion on the upper surface of the suction block 2.
The through hole 26 includes a small diameter portion and a large diameter portion formed on each of the upper surface side and the lower surface side of the small diameter portion.

A stepped pipe 27 is inserted into the through hole 26 from the lower surface side of the suction block 2. An O-ring 271 is disposed between the pipe 27 and the through hole 26 to prevent liquid leakage from the gap between the through hole 26 and the pipe 27.
Further, a nozzle 28 is inserted into the through hole 26 from the lower surface side. The nozzle 28 is fixed by a fixing screw 29 screwed into the through hole 26.

A base member 7 is attached to the attachment hole 25. As shown in FIG. 4, the base member 7 is formed in a substantially disk shape, and is attached by inserting five pins protruding from the lower surface thereof into the attachment hole 25.
On the upper surface of the base member 7, a recess forming surface 71 that is a diaphragm contact surface facing the pump block 3 is provided. The recess forming surface 71 is a flat portion formed in a substantially circular shape. A port 72 that is inserted through the pipe 27 is formed at the center axis portion of the recess forming surface 71, and a plurality of recesses 73 to 75 are formed around the port 72.
That is, the concave portion forming surface 71 includes a first concave portion 73 formed along the outer periphery of the concave portion forming surface 71, a second concave portion 74 formed on the inner peripheral side thereof, and an inner peripheral side thereof, that is, around the port 72. And a third concave portion 75 disposed in the inner space. Each of the recesses 73 to 75 is a spherical recess.

A cutout 76 communicating with the first recess 73 is formed on the side surface of the base member 7. Each notch 76 communicates with the suction channel 23, and the liquid supplied to the suction channel 23 can be supplied to each first recess 73 via the notch 76. For this reason, the suction flow path 23 extends from a portion communicating with the port 24 to a position where it can communicate with at least five notches 76 provided in the base member 7 and is formed in a substantially C-shaped plane.
The second recess 74 is communicated with the first recess 73 via the communication groove 77, and is communicated with the third recess 75 via the communication groove 78. The third recess 75 communicates with the port 72, that is, the pipe 27 via the communication groove 79.

  Accordingly, the first concave portion 73, the second concave portion 74, the third concave portion 75, the notch 76, and the communication grooves 77 to 79 formed on the concave portion forming surface 71 which is the diaphragm close surface of the base member 7 are formed on the diaphragm close surface. The liquid channel is formed by the space defined by the concave groove and the diaphragm 8. In this embodiment, five (5 sets) of liquid channels are provided.

Each recess 73, 74, 75 is set such that the length from the center of the port 72 to the center of each recess 73, 74, 75 is gradually reduced. Accordingly, the concave portions 73, 74, and 75 are arranged in a spiral shape (spiral shape) around the port 72.
In this embodiment, five sets of the recesses 73 to 75 are arranged, and the first recesses 73 are arranged around the port 72 at a pitch of 360/5 = 72 degrees. The other second recesses 74 and the third recesses 75 are also arranged at a pitch of 72 degrees.
Further, in the present embodiment, the first concave portion 73 constitutes the suction side valve chamber concave portion, the second concave portion 74 constitutes the measuring chamber concave portion, and the third concave portion 75 constitutes the discharge side valve chamber concave portion. Yes.

  As shown in FIG. 2, a diaphragm 8 is attached to the upper surfaces of the suction block 2 and the base member 7. That is, the peripheral edge of the diaphragm 8 is disposed in the ring-shaped diaphragm locking groove 22 of the suction block 2. The edge of the diaphragm 8 is sandwiched between a suction block 2 and a pump block 3 fixed by screws 10.

The diaphragm 8 is an elastic body made of elastically deformable rubber (synthetic rubber, natural rubber) or the like, and is formed in a substantially disk shape. The upper and lower surfaces of the diaphragm 8 are formed in a flat shape. The thickness of the diaphragm 8 is about 1 mm.
At this time, the space between the upper surface of the suction block 2 and the lower surface of the pump block 3 is slightly smaller than the thickness of the diaphragm 8, for example, 0.9 mm. Therefore, when the blocks 2 and 3 are assembled with the screws 10, the peripheral edge of the diaphragm 8 is sandwiched and compressed by the blocks 2 and 3, and the diaphragm 8 is held at a predetermined pressure.

A guide member 30 is disposed in the central through hole portion of the pump block 3. A guide push ring 40 and a disc spring 41 are disposed in the through hole at the center of the holding block 4. The guide member 30 is urged toward the diaphragm 8 by the disc spring 41 through the guide push ring 40.
For this reason, the diaphragm 8 is pressed with a predetermined pressure on a planar portion other than the recesses 73 to 75 and the communication grooves 77 to 79 on the recess forming surface 71 of the base member 7. Accordingly, each of the recesses 73 to 75 is partitioned by the diaphragm 8 that is in close contact with the recess forming surface 71, and can communicate with the suction flow path 23, the other recesses 73 to 75, and the pipe 27 only by the notch 76 and the communication grooves 77 to 79. It is configured. For this reason, the suction side valve chamber is configured by the space defined by the first recess 73 and the diaphragm 8, and the measurement chamber is configured by the space defined by the second recess 74 and the diaphragm 8, and the third recess 75 and the diaphragm 8 are configured. The discharge side valve chamber is constituted by the space partitioned by. In addition, each communication path is configured by a space defined by the notch 76, the communication grooves 77 to 79, and the diaphragm 8. The liquid flow path is configured to include these valve chambers, a measurement chamber, and a communication path.

  The guide member 30 is formed in a substantially columnar shape, and a guide hole 32 corresponding to a position where the concave portions 73 to 75 of the base member 7 are formed is formed in the axial direction. Each guide hole 32 has a step formed at an axially intermediate portion and has a different diameter. The lower surface side is a small diameter hole portion, and the upper surface side is a large diameter hole portion having a larger diameter than the small diameter hole portion.

In each guide hole 32, pressing rods 33 to 35 that are pressing members are inserted. That is, the first pressing rod 33 is inserted into the guide hole 32 corresponding to the first recess 73, the second pressing rod 34 is inserted into the guide hole 32 corresponding to the second recess 74, and the third The third pressing rods 35 are inserted into the guide holes 32 corresponding to the recesses 75, respectively. A suction-side pressing member is configured by the first pressing rod 33 provided corresponding to the suction-side valve chamber, and a measuring chamber pressing member is configured by the second pressing rod 34 provided corresponding to the measuring chamber. The discharge-side pressing member is constituted by the third pressing rod 35 provided corresponding to the discharge-side valve chamber.
Each of the pressing rods 33 to 35 has a stepped shape and is urged in a direction away from the diaphragm 8 by a coil spring 38 disposed in the guide hole 32.

The end surfaces of the pressing rods 33 to 35 on the diaphragm 8 side are formed in a spherical shape. For this reason, when each pressing rod 33-35 is moved to the diaphragm 8 side, the diaphragm 8 is comprised so that it may closely_contact | adhere to the spherical surface of each recessed part 73-75. However, since the communication grooves 77 to 79 have a small width dimension, the diaphragm 8 does not enter the communication grooves 77 to 79, and the communication grooves 77 to 79 are always maintained in a communication state.
On the other hand, a substantially hemispherical recess is formed on the other end face of the pressing rods 33 to 35, and a ball 39 is accommodated in the recess.

The motor mounting block 5 includes a cylindrical insertion portion 5A that is inserted into the through hole of the holding block 4 and a flange portion 5B that is formed with a through hole through which the screws 11 and 12 are inserted. Yes. A through hole having a substantially circular cross section is also formed in the central axis portion of the motor mounting block 5.
Driving means for driving the pressing rods 33 to 35 are disposed in the through hole portions of the holding block 4 and the motor mounting block 5.
That is, a cam 51 that is rotationally driven by the drive unit 6 is disposed in the internal through hole of the holding block 4. The cam 51 may be directly attached to the output shaft 61 of the drive unit 6, but in this embodiment, the cam 51 is attached to the output shaft 61 via the spline boss 52 and the spline shaft 53. That is, the spline shaft 53 is attached to the output shaft 61 by the pin 54 so as to be integrally rotatable. A spline boss 52 is press-fitted into the cam 51. The spline boss 52 and the cam 51 are configured to be slidable in the axial direction of the output shaft 61 with respect to the spline shaft 53 and to be rotatable integrally with the spline shaft 53 and the output shaft 61.

The cam 51 and the spline boss 52 are supported by a ball bearing 55 so as to be rotatable with respect to the motor mounting block 5. The ball bearing 55, the spline boss 52, and the cam 51 are urged toward the guide member 30 by the disc spring 57 via the spacer ring 56. Further, since the pressing rods 33 to 35 are biased toward the cam 51 by the coil spring 38, the cam surface 511 of the cam 51 is always in contact with the ball 39.
The urging force of the disc spring 57 is set larger than the total value of the urging forces of the coil springs 38, and the pressing rods 33 to 35 are diaphragms by the disc spring 57 via the cam 51, the spline boss 52, and the ball bearing 55. 8 is biased in the direction approaching 8, that is, in the first direction. Therefore, the disc spring 57 constitutes a pressing member urging means for urging the pressing rods 33 to 35 as pressing members in the first direction.
The coil spring 38 constitutes a contact urging means that urges the pressing rods 33 to 35 in the direction away from the diaphragm 8, that is, in the second direction to abut against the cam surface 511 of the cam 51.

The cam 51 is constituted by an end face cam (solid cam) having a cam face 511 formed on the end face, and the cam face 511 has a cam shape corresponding to a predetermined cam diagram. That is, the cam 51 has a through hole formed in the central shaft portion, and a cam surface 511 formed in a ring shape around the hole.
In the present embodiment, the cam surface 511 is one cycle at 90 °, and 90 ° to 180 °, 180 ° to 270 °, and 270 ° to 360 ° are repeated. To do. In the following description, y represents the axial position of the cam surface 511, the cam surface 511 closest to the diaphragm 8 side is the lowest cam position (y = 0), and the farthest portion is the highest cam position (main In an example of the embodiment, for example, y = 0.5 mm). On the other hand, x is 0 ° when the ball 39 of the first pressing rod 33 is in contact with the lowest cam position (y = 0), and the rotation angle of the cam 51 from that position, that is, the cam surface 511 with respect to the ball 39. Relative rotation angle.

The cam surface 511 in which the rotation angle of the cam 51 is 0 ° to 12 ° remains in the lowest position (y = 0). That is, the cam surface 511 of that portion is configured by a plane orthogonal to the rotation axis of the cam 51.
The cam surface 511 from 12 ° to 24 ° has a circumferential shape, for example,
y = (x-12) is a quadratic curve expressed by ^2/864.
The cam surface 511 from 24 ° to 30 ° has a circumferential shape, for example,
y = x / 36-1 / 2.

The cam surface 511 from 30 ° to 42 ° has a circumferential shape, for example,
y = - (x-42) is a quadratic curve expressed by ^2/864 + 1/2.
The cam surface 511 from 42 ° to 48 ° remains in the cam maximum position (y = 0.5).
The cam surface 511 from 48 ° to 60 ° has a circumferential shape, for example,
y = - (x-42) is a quadratic curve expressed by ^2/864 + 1/2.

The cam surface 511 from 60 ° to 66 ° has a circumferential shape, for example,
It is a straight line represented by y = −x / 36 + 2.
The cam surface 511 from 66 ° to 78 ° has a circumferential shape, for example,
It is a quadratic curve expressed by ^{y = (x-78) 2} /864.
From 78 ° to 90 °, the cam surface 511 remains in the lowest position (y = 0).

  Each of the cam surfaces is formed radially from the central axis of the cam surface 511. That is, the boundary line of each cam surface 511 is a straight line arranged radially from the central axis of the cam surface 511.

Accordingly, when the spline shaft 53, the spline boss 52, and the cam 51 are rotated by the drive unit 6, the ball 39 and the pressing rods 33 to 35 advance and retreat in the axial direction along the shape of the cam surface 511. When the pressing rods 33 to 35 move to the concave portions 73 to 75, a section is formed by the portions corresponding to the concave portions 73 to 75 of the diaphragm 8 (the concave portion corresponding portions where the pressing rods 33 to 35 abut on the diaphragm 8) and the concave portions 73 to 75. The volume of each of the valve chambers and the measurement chambers to be reduced is reduced, and finally, the concave portion corresponding portions are in close contact with the inner surfaces of the concave portions 73 to 75. That is, the pressing rods 33 to 35 perform a volume reducing operation.
In addition, when the pressing rods 33 to 35 move away from the recesses 73 to 75 from this state, the recess-corresponding portion of the diaphragm 8 is separated from the inner surface of the recesses 73 to 75 that are in close contact, and the space between the recesses 73 to 75 and the diaphragm 8 is reached. The volume of each valve chamber or metering chamber that is partitioned is increased. That is, the pressing rods 33 to 35 perform a volume increasing operation.
For this reason, in this embodiment, the drive unit is configured to include the drive unit 6, the spline shaft 53, the spline boss 52, the cam 51, and the coil spring 38 that is a biasing means for contact.

Here, the material of the pressure rods 33 to 35, the ball 39, the cam 51, and the coating treatment are performed so that the friction coefficient between the pressing rods 33 to 35 and the ball 39 is lower than the friction coefficient between the ball 39 and the cam surface 511. Presence or absence, coating method, etc. are set.
Specifically, the ball 39 is a hard ball made of a superhard alloy such as tungsten carbide. The cam 51 is also made of a hardened and polished metal such as carbon tool steel, and the cam surface 511 is hard.
On the other hand, each of the pressing rods 33 to 35 and the spline boss 52 can be made of plastic (synthetic resin). Here, the pressing rods 33 to 35 are usually made of a soft resin material as compared with the ball 39, but the surface of the pressing rods 33 to 35 may have the same hardness as the ball 39 by DLC coating or the like. . In short, each material or the like may be selected so that the friction coefficient with the ball 39 is lower on the side of each pressing rod 33 to 35 than on the cam surface 511. Each of the pressing rods 33 to 35 is soft compared to the ball 39, and the displacement of the cam surface 511 must be transmitted to the diaphragm 8 through the ball 39 and the pressing rods 33 to 35. Therefore, the strength that prevents deformation by such contact is ensured.

The drive unit 6 may be a rotational drive source capable of rotating the output shaft 61, and various motors can be used. In this embodiment, it is comprised with the servomotor with a reduction gear.
On the side surface of the holding block 4, screw holes for attaching the diaphragm pump 1 to various manufacturing apparatuses, robot arms, and the like are formed.

  In the present embodiment, since the liquid is transferred for each of the five liquid channels, it can be said that a pump is configured for each liquid channel. In other words, in this embodiment, liquid is transferred by each valve chamber, measurement chamber (recesses 73 to 75), pressing rods 33 to 35, communication passages (notches 76, communication grooves 77 to 79), and the diaphragm 8 provided in the liquid flow path. A plurality of pumps are configured, and a diaphragm pump 1 that can continuously transfer a certain amount of liquid with less pulsation is configured by the plurality of pumps.

The diaphragm pump 1 according to the present embodiment operates in the same manner as the pump disclosed in Patent Document 1 by the operation of the pressing rods 33 to 35 according to the shape of the cam surface 511 of the cam 51.
That is, the diaphragm 8 moves in a direction in close contact with the recesses 73 to 75 in accordance with the advancement and retraction of the push rods 33 to 35 to reduce the volumes of the valve chambers and the measurement chambers or to move away from the recesses 73 to 75. By moving and greatly expanding the volume of each valve chamber or measuring chamber, liquid is sucked into or discharged from each valve chamber or measuring chamber.
Specifically, by rotating the cam 51, the second pressing rod 34, which is a pressing member for the measuring chamber provided corresponding to the measuring chamber, is moved in the first direction to correspond to the measuring chamber of the diaphragm 8. The portion to be sealed is brought into close contact with the second recess 74 to seal the measuring chamber, and the first pressing rod 33 which is a suction side pressing member provided corresponding to the suction side valve chamber is moved in the second direction to form a diaphragm. A suction step for separating the portion corresponding to the suction side valve chamber 8 from the first recess 73 and sucking the liquid from the suction flow path 23 into the suction side valve chamber, and a discharge side pressure provided corresponding to the discharge side valve chamber The third pressing rod 35, which is a member, is moved in the first direction, the portion corresponding to the discharge side valve chamber of the diaphragm 8 is brought into close contact with the third recess 75, the discharge side valve chamber is sealed, and the second press Move the rod 34 in the second direction The portion of the diaphragm 8 corresponding to the measuring chamber is separated from the second recess 74 to increase the volume of the measuring chamber, and the first pressing rod 33 is moved in the first direction to correspond to the suction side valve chamber of the diaphragm 8. In the first recess 73 side, the volume of the suction side valve chamber is reduced and the liquid is transferred from the suction side valve chamber to the measuring chamber, and the discharge side valve chamber is kept sealed, The first pressing rod 33 is moved in the first direction so that a portion corresponding to the suction side valve chamber of the diaphragm 8 is brought into close contact with the first recess 73 to seal the suction side valve chamber, and the liquid is discharged to the suction side valve chamber and the discharge side. A metering step for measuring by dividing between the side valve chambers, and reducing the volume of the metering chamber by moving the second pressing rod 34 in the first direction while keeping the suction side valve chamber sealed; 3 press b A second transfer step of transferring the liquid from the metering chamber to the discharge side valve chamber by moving the nozzle 35 in the second direction to increase the volume of the discharge side valve chamber; Is moved in a direction approaching the third recess 75 to reduce the volume of the discharge side valve chamber, transfer the liquid from the discharge side valve chamber to the discharge side port 72, and discharge the liquid from the nozzle 28 via the pipe 27. The discharging process is sequentially performed by each pump, and the liquid is discharged.

[Release urging force against pressing rod]
When the diaphragm pump 1 is assembled or when the pump driving is stopped, the screw 11 is loosened and the motor mounting block 5 is slid in the second direction with respect to the holding block 4 as shown in FIG. Let At this time, the motor mounting block 5 is movable until it is locked to the head of the screw 12.

When the motor mounting block 5 is moved in the second direction, the distance between the ball bearing 55 on which the disc spring 57 is disposed and the motor mounting block 5 also increases, so that the biasing force applied to the cam 51 by the disc spring 57 is released. . Therefore, in this embodiment, a spring receiving member is constituted by the motor mounting block 5, and the urging force releasing means is configured by including the motor mounting block 5, the screws 11, 12 and the like.
When the urging force of the disc spring 57 is released, the pressing rods 33 to 35 are moved in the second direction by the urging force of the coil spring 38. Therefore, the lower ends (end portions on the diaphragm 8 side) of the pressing rods 33 to 35 move upward from the end surface of the guide member 30, and at least the lower ends of the pressing rods 33 to 35 do not protrude from the guide member 30.
Therefore, when the diaphragm 8 is mounted on the suction block 2, the diaphragm 8 can be set in a flat state by moving the motor mounting block 5 and releasing the urging force of the disc spring 57. Further, the diaphragm pump 1 used in a production line or the like is pressed against the diaphragm 8 by moving the motor mounting block 5 and releasing the urging force of the disc spring 57 during the stop time period of the line such as at night. It is possible to prevent the pressing force by the rods 33 to 35 from being constantly applied.

According to the present embodiment as described above, the same effects as in Patent Document 1 can be obtained, and the following effects can be obtained.
(1) Since the urging force of the disc spring 57 that urges the pressing rods 33 to 35 toward the diaphragm 8 side can be released, the diaphragm 8 is in a state where the pressing rods 33 to 35 do not protrude from the guide member 30. Can be set. For this reason, since the diaphragm 8 is set in a state where the push rods 33 to 35 protrude, the diaphragm pump 1 of the present embodiment is different from the conventional diaphragm pump in which the periodic discharge amount error occurs. Can be set flat, thus preventing periodic discharge amount errors.

(2) Further, when the diaphragm pump 1 is not used, if the motor mounting block 5 is moved, the pressing force applied by the pressing rods 33 to 35 to the diaphragm 8 can be released. For this reason, when the diaphragm 8 is always pressed by the pressing rods 33 to 35, the diaphragm 8 is permanently deformed, and the period for replacing the diaphragm 8 is also shortened. However, in the present embodiment, the diaphragm pump 1 When not in use, the pressing force by the pressing rods 33 to 35 is not applied, and the diaphragm 8 can be hardly permanently deformed. For this reason, the period until the diaphragm 8 is replaced can be lengthened, and the replacement cost of the diaphragm 8 can be reduced.

(3) Furthermore, since the screw 12 for restricting the movement of the motor mounting block 5 in the second direction is provided, the motor mounting block 5 and the holding block 4 are completely separated when the screw 11 is removed. Can be easily prevented. For this reason, when the motor mounting block 5 and the holding block 4 are joined again, it is only necessary to tighten the screw 11, and the diaphragm pump 1 can be returned to a usable state by a simple operation.

(4) Since the motor mounting block 5 has the insertion portion 5A inserted into the through hole in the holding block 4, the motor mounting block 5 can be easily moved relative to the holding block 4 by loosening the screw 11. Can slide. For this reason, the urging force of the disc spring 57 can be released by a simple operation of loosening the screw 11, and the operability can be improved. In addition, since the structure for releasing the biasing force of the disc spring 57 is simple, the cost can be reduced.

(5) Since the disc spring 41 that biases the guide member 30 toward the diaphragm 8 is provided separately from the disc spring 57, the diaphragm 8 is brought into close contact with the recess forming surface 71 of the base member 7 with a predetermined pressing force. Can do. For this reason, even if the processing accuracy of the guide member 30 and the base member 7 is somewhat low, the concave portions 73 to 75 of the base member 7 can be reliably partitioned, and a decrease in accuracy of the liquid transfer amount can be prevented.

  The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

  The liquid discharge device of the present invention is not limited to the one using the diaphragm 8 as the elastic body, but may be a tube pump using a tube as the elastic body. That is, by moving the pressing member in the first direction approaching the tube and crushing the tube, the tube is closed, or by moving in the second direction away from the tube and releasing the crushed tube, inhalation The liquid may be sucked and discharged by opening and closing the side valves and the discharge side valves and changing the volume of the measuring chamber disposed between the valves.

The structure of the drive mechanism that drives the cam 51 is not limited to that of the above embodiment. For example, the cam 51 may be directly fixed to the output shaft without using the spline boss 52 or the spline shaft 53.
Various motors such as a stepping motor, a servo motor, a synchronous motor, a DC motor, an induction motor, a reversible motor, and an air motor can be used as the motor.

The material of the diaphragm 8 is not limited to rubber, and may be a laminate of fluororesin or the like and rubber. According to such a configuration, the surface of the diaphragm 8 that is in contact with the liquid is made of a fluororesin having high chemical resistance, so that the types of liquid that can be used can be greatly increased and can be used for various applications. In short, the diaphragm 8 is an elastically deformable material that can be deformed by the pressing force of the pressing rods 33 to 35 and can return to its original state when the pressing force of the pressing rods 33 to 35 is released. If it is.
If a material that is hard to deform compared to rubber such as fluororesin is used, the depth dimension of the recesses 73 to 75 is reduced to, for example, about 0.1 mm, or the shape is devised for modification. What is necessary is just to comprise so that the diaphragm 8 with few quantity can contact | adhere to the recessed parts 73-75. In short, the shapes and dimensions of the recesses 73 to 75 may be appropriately set according to the material of the diaphragm 8 to be used and the amount of liquid transferred.

In the above embodiment, the base member 7 is configured separately from the suction block 2, but a recess forming surface that is in close contact with the diaphragm 8 may be formed on the suction block 2. However, if the base member 7 is configured separately from the suction block 2, for example, the base member 7 can be configured by a resin molded product or the like. Compared to the case of forming 75, the processing accuracy can be improved.
Further, the configuration of the pressing member urging means is not limited to the disc spring 57, and any configuration can be used as long as the pressing member can be urged in the first direction.

It is a figure which shows 1st Embodiment of this invention. It is sectional drawing of the principal part of the said embodiment. It is a top view which shows the suction block of the said embodiment. It is a top view which shows the recessed part formation surface of the base member of the said embodiment. It is sectional drawing of the principal part of the said embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Diaphragm pump, 2 ... Suction block, 3 ... Pump block, 4 ... Holding block, 5 ... Motor mounting block, 6 ... Drive unit, 7 ... Base member, 8 ... Diaphragm, 30 ... Guide member, 33 ... 1st press Rod, 34 ... second pressing rod, 35 ... third pressing rod, 38 ... coil spring, 41 ... disc spring, 51 ... cam, 57 ... disc spring, 71 ... recessed surface, 73 ... first recess, 74 ... second Recess, 75 ... third recess.

Claims (3)

A liquid ejection apparatus comprising a case, a drive device main body provided in the case, and an elastic body attached to the case,
The elastic body is composed of a diaphragm or a tube,
The drive device body is
A plurality of pressing members provided movably in a first direction approaching the elastic body and in a second direction away from the elastic body;
Pressing member biasing means for biasing each pressing member in the first direction;
Driving means for individually moving the pressing members in the second direction against the biasing force of the pressing member biasing means;
Urging force releasing means for releasing the urging force by the pressing member urging means;
A liquid ejection apparatus comprising: The liquid ejection apparatus according to claim 1,
In the case, a guide block for guiding each pressing member is provided,
The drive means is disposed in the guide block, a rotation drive source, a cam that is movable in the direction of the rotation axis with respect to the output shaft of the rotation drive source, and is rotatable together with the output shaft. A contact urging means for urging each pressing member in the second direction to abut against the cam surface of the cam;
The biasing force releasing means is configured to include a spring receiving member that is disposed on the second direction side of the cam and is slidable within a predetermined range along the first direction and the second direction.
The pressing member urging means is configured by a spring disposed between the cam and the spring receiving member,
In a state where the spring receiving member is moved to the stroke end position on the first direction side, the pressing member is biased in the first direction by the pressing member biasing means,
In a state where the spring receiving member is moved to the stroke end position on the second direction side, the urging force of the pressing member is released by the pressing member urging means, and the second force is applied by the abutting urging means. A liquid ejecting apparatus, wherein the liquid ejecting apparatus is biased in a direction and moved to a position where an end of the pressing member on the first direction side does not protrude from the guide block. The liquid ejection apparatus according to claim 2, wherein
The elastic body is composed of a diaphragm,
The liquid ejecting apparatus according to claim 1, wherein the guide block is urged in a first direction by a guide block urging unit and is in close contact with the diaphragm.

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