JPH06129345A - Plunger pump - Google Patents

Abstract

PURPOSE:To provide a plunger pump which can suck and discharge liquids at high accuracy, has high durability and is easy to handle. CONSTITUTION:A valve block 30 having communicating holes 31, 32 for intake and delivery ports 21, 22 and a pump block 40 having a plunger insertion hole 42 into which a plunger 45 is inserted are both made from a hard material such as alumina ceramics. Even if the blocks 30, 40 are pressed by a cone spring 51 and forced into contact with each other at their respective sliding surfaces 33, 41 in order to provide a seal for preventing liquid leaks, the blocks are not broken since they are made from hard material and have high durability. Also, the need for finely controlling the pressing force is eliminated so that the plunger pump is easy to handle. Further, since the hard material resists deformation, quantities of liquids can be measured at the plunger insertion hole 42 and the valve block 30 at high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plunger pump that sucks and discharges liquid by utilizing the reciprocating motion of a plunger.

[0002]

2. Description of the Related Art Conventionally, various types of pumps of this type have been known, and an example of this type of pump is described in Japanese Utility Model Laid-Open No. 2-78773. This pump has a valve block having a sliding contact surface with communication holes that communicate with the suction port and the discharge port, and rotates on the body with one sliding contact surface abutting against the sliding contact surface of the valve block. A pump block having a plurality of plunger insertion holes bored in the axial direction in a state of being freely supported and communicating with the opening of the communication hole of the valve block, and the pump block is provided on the valve block side. The plunger insertion hole is sequentially communicated with the communication hole by urging while being urged, and the plungers in the plunger insertion hole are each driven in the axial direction to sequentially repeat suction and discharge of the liquid.

In the pump, one of the valve block and the pump block is made of a hard material such as stainless steel, and the other is made of an elastic resin such as Teflon or polypropylene, and the block of the hard material is made of an elastic resin. The liquid is prevented from leaking from the sliding contact surfaces of the valve block and the pump block that are in rotary sliding contact by pressing the resin against the block to slightly deform the resin.

[0004]

By the way, although the pump can be provided at a low price and has no problem in general use, it may not be able to meet the demand for high performance. That is, the pump slightly deforms the resin to improve the sealing performance of the sliding contact surface, but the degree of this deformation causes a slight error in the amount of liquid sucked into the plunger insertion hole, resulting in extremely high accuracy. In some cases, it was not possible to meet the demand for the discharge amount.

Further, one of the blocks made of resin and the other made of a hard material are urged against the other to be brought into sliding contact with each other. However, when the urging force becomes large, the resin is scraped off, the durability performance deteriorates, and the urging force is increased. If it is too small, the sealing property of the sliding contact surface deteriorates, which makes it difficult to adjust the biasing force. Furthermore, even if the urging force is adjusted appropriately, the resin block is slightly scraped away, so the resin block must be replaced when used for a long time, and durability is not very high. There was also a problem.

An object of the present invention is to provide a plunger pump which can suck and discharge a liquid with high precision, has high durability and is easy to handle.

[0007]

SUMMARY OF THE INVENTION According to the present invention, each member which is relatively slidably contacted by rotation is formed of a hard material such as ceramic, and both are brought into contact with each other with a predetermined pressure, and one of them is not made of an elastic resin. It was made by finding that it can be sealed.
Specifically, a body, a valve block which is attached to the body and has a sliding contact surface in which communication holes communicating with the intake port and the discharge port are opened, and a sliding contact surface of the valve block at one end. A pump block that is rotatably supported by the body with its contact surface abutted and that has a plunger insertion hole that is bored in the axial direction while being able to communicate with the opening of the communication hole of the valve block. An urging means for urging the pump block toward the valve block side, a rotational drive means for rotationally driving the pump block, and a plunger axially slidably inserted in a plunger insertion hole of the pump block, This plunger is driven in the axial direction, and the plunger insertion hole of the pump block communicates with the suction port through the communication hole. The plunger advancing / retreating drive means for driving the plunger in the discharge direction with the plunger insertion hole communicating with the discharge port through the communication hole, and the plunger advancing / retreating driving means. A plunger seal mechanism for sealing a plunger insertion hole of the pump block is provided, and the valve block and the pump block are each made of a hard material.

In the present invention, as the hard material, ceramic, cemented carbide or the like is used. Further, it is preferable that a recess is formed at least in the center of the sliding contact surface of the valve block. In addition, the plunger pump has
In addition to the primary seal composed of the sliding contact surfaces of the valve block and pump block and the plunger seal mechanism,
It is preferable to provide a secondary seal for preventing the liquid from leaking to each driving means side when there is a liquid leaking from the secondary seal. The plunger insertion hole and the plunger may be provided one by one, or two.
One or more may be provided in plurality.

[0009]

In the present invention, the pump block rotated by the rotation driving means is brought into contact with the valve block attached to the body at a predetermined pressure by the biasing means. In the rotating state of the pump block, the plunger is moved by the plunger driving means in the suction direction at a position communicating with the suction port, that is, in the direction away from the valve block, and sucks a predetermined liquid from the suction port.

In this suction state, when the pump block rotates and the plunger insertion hole reaches the position communicating with the discharge port, the plunger is moved by the plunger driving means in the discharge direction, that is, the direction close to the valve block. The sucked liquid is discharged from the discharge port. Thereafter, while maintaining the discharge state, the suction port side is rotated again, the suction port side is moved in the suction direction in the same manner as described above, and the suction and the discharge are sequentially repeated in the same manner.

In the suction and discharge operations, since the pump block and the valve block are made of a hard material such as ceramic, they can be pressed against each other with a relatively large urging force, and the sliding contact surfaces of the blocks come into close contact with each other. Therefore, there is no leakage of liquid between the suction port side and the discharge port side at this portion, and complete sealing is performed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. The plunger pump 1 is, as shown in FIG.
The body 10 includes a main cylinder 11, a cap 12 bolted to one end of the main cylinder 11, and a main cylinder 11.
It is composed of a connection cylinder 14 bolted to the other end of the main cylinder 11 via a cam 13.

The cap 12 of the body 10 is shown in FIG.
The port block 20 with a collar is inserted as shown in FIG. 3, and is bolted to the cap 12 at the collar as shown in FIG. Further, the port block 20 includes an intake port 21 and a discharge port 22 each having a female screw formed therein.

In the cap 12, a valve block 30 integrally formed of a hard material such as alumina ceramic is arranged in a state of being prevented from rotating by a pin or the like not shown. The valve block 30 is formed with communication holes 31 and 32 which communicate with the intake port 21 and the discharge port 22 of the port block 20, and these communication holes 31 and 32 are smooth and formed on the inner end surface of the valve block 30. Each of the sliding contact surfaces 33 has an opening.

As shown in FIGS. 3 and 4, the openings of the communication holes 31 and 32 are semi-circular grooves 34 and 3, respectively.
It is said to be 5. The sliding contact surface 33 is provided between the grooves 34 and 35.
A long groove 36 for removing dust and the like that passes through the center of is formed. Further, a ring-shaped sealing material 15 is interposed at the connecting portion between the valve block 30 and the cap 12 for sealing.

In the cap 12, a cylindrical pump block 40 is rotatably arranged adjacent to the valve block 30. The pump block 40 is made of a hard material such as alumina ceramic, and has a smooth sliding contact surface 41 that is in sliding contact with the sliding contact surface 33 of the valve block 30 at one end.
have. One of the sliding contact surface 41 and the sliding contact surface 33 of the valve block 30 has a surface roughness of 0.01 to 0.15 μmRa and the other has a surface roughness of 0.2 to 0.4 μmRa. Both are considered to have satisfactory surface roughness.

Further, a plurality of, for example, three plunger insertion holes 42 are formed in the pump block 40 so as to penetrate the pump block 40, and an end portion of the plunger insertion hole 42 opposite to the sliding contact surface 41 is formed. It is a large diameter portion 42A.

The opening of each plunger insertion hole 42 on the side of the sliding contact surface 41 has two grooves 34, 35 of the valve block 30.
The plunger insertion hole 42 and the grooves 34, 35 are formed at positions that can face each other.
When the plunger 45 inserted into the valve is sucking or discharging, that is, when the plunger 45 slides in the axial direction, it is communicated with either of the grooves 34 and 35.
On the other hand, when the plunger insertion hole 42 is away from the grooves 34 and 35, the size and position are set so that the suction or discharge operation is not performed.

Plunger insertion hole 4 of pump block 40
A substantially conical convex seal 71, which is a plunger seal mechanism 70, is inserted into the second large-diameter portion 42A, and liquid leaks from a gap between the plunger 45 and the plunger insertion hole 42 that penetrates the convex seal 71. It is sealed to prevent it. The convex seal 71 and the sliding contact surfaces 33, 41 of the valve block 30 and the pump block 40 form a primary seal of the plunger pump 1.

A pump block 40 is provided in the cap 12.
A spring guide block 50 is disposed adjacent to the spring guide block 50.
A disc spring 51 serving as a biasing means is interposed between the spring guide block 50 and the bearing 17 arranged in the main cylinder 11 of the body 10. By the biasing force of the disc spring 51, the pump block 40 is biased toward the valve block 30 side via the spring guide block 50, and the sliding contact surface 33 of the valve block 30 and the sliding contact surface 4 of the pump block 40.
1 is in sliding contact with a predetermined pressure.

The pump block 40 and the spring guide block 50 are connected to the block 50 by three connecting pins 43 projecting from the contact surface of the pump block 40 with the block 50 at equal intervals of 120 degrees. By being inserted into a communication hole 52 formed so as to face the pin 43, it can be integrally rotated.

Plunger 45 of spring guide block 50
In the spring guide hole 53 in which is arranged, a spring receiver 54 is arranged adjacent to the convex seal 71 so that the plunger 45 can penetrate therethrough. Between the spring receiver 54 and the spring receiver 55 fitted to the right end side of the plunger 45 in the drawing, the pressing spring 5 which is an urging member formed of a compression coil spring.
6 is interposed. The pressing spring 56 presses the convex seal 71 against the bottom of the large diameter portion 42A with a predetermined pressure, while urging the plunger 45 in the protruding direction.

Further, in the spring guide hole 53, a U seal receiver 72 is arranged adjacent to the spring receiver 55.
The U-seal receiver 72 has an entire circumferential groove formed in the middle thereof, and a U-seal 73 formed of a ring having a U-shaped cross section is interposed in the entire circumferential groove. Further, a ring-shaped seal 16 is interposed between the outer peripheral surface of the spring guide block 50 and the inner peripheral surface of the cap 12 of the body 10. Each of these seals 1
A secondary seal is composed of 6, 73, and suction and suction is performed from each sliding contact surface 33, 41 or the convex seal 71, which is a primary seal.
Even if the discharged liquid leaks, it can be prevented from leaking to the drive unit side, and the oil of the drive unit can be prevented from entering the pump.

The convex seal 71 which is the primary seal, the U seal 73 which is the secondary seal, and the seal 16 are made of an appropriate material such as synthetic resin or rubber. Particularly, the primary seal which is in direct contact with the liquid is In addition to having chemical resistance,
It is preferably formed of a glass-containing tetrafluoroethylene copolymer (trade name: Teflon) or the like, which is not easily deformed and causes little error in measuring the liquid. On the other hand, since the secondary seal that prevents only the leakage of the liquid does not require a decrease in accuracy due to deformation or the like, inexpensive rubber or the like can be used.

On the right end side in the figure, which is one end side of the spring guide block 50, the rotating body 61 is provided with the main cylinder 11 and the cam 13.
It is rotatably arranged inside through bearings 17 and 18. On the end surface of the rotating body 61 on the guide block 50 side, three connecting pins 62 are provided so as to project at equal intervals of 120 degrees, and these connecting pins 62 are inside a connecting hole 57 opened on the end surface of the block 50. The rotation of the rotating body 61 is transmitted to the block 50.

Further, the right end side of the rotating body 61 in the drawing is 120
Three connecting pins 63 are projectingly provided at equidistant positions, and these connecting pins 63 are respectively inserted into vertical grooves 64A of a connecting sleeve 64 arranged adjacent to the rotating body 60. A connecting pin 68 protruding from a coupling 67 fixed to an output shaft 66 of the motor 65 is also inserted in the vertical groove 64A of the connecting sleeve 64. Here, the motor 65,
Coupling 67, connecting sleeve 64, rotating body 61, spring guide block 50 and connecting pins 43, 62, 6
The rotation driving means 6 for the pump block 40 is provided by
0 is configured, and the rotation of the motor 65 causes the pump block 40 to rotate.
To be transmitted smoothly.

Inside the rotating body 61, three rods 81, which are also arranged at 120 ° equidistant positions facing the three plungers 45 inserted into the plunger insertion holes 42 of the pump block 40, are bearings. It is inserted via 82 so as to be slidable in the axial direction. A follower holder 83 is pinned in the middle of the rod 81 in a recess 61B formed in the middle of the rotating body 61.

Further, the follower holders 83 are provided with shafts 83B, respectively, and a cam follower 84 consisting of two rollers is rotatably attached to each of these shafts 83B. Each of these cam followers 84 is guided in axial follower guide holes 61C formed at 120 ° equidistant positions on the peripheral surface of the rotary body 61 so as to be axially movable and immovable in the rotational direction.

Further, the cam follower 84 includes the cam 13
The cam surface 13A formed on the end surface of the cam follower is contacted by the pressing force of the pressing spring 56, and as the rotating body 61 rotates, the cam follower 84 moves back and forth in the axial direction along the shape of the cam surface 13A. Rod 81 via holder 83
In this case, the rod 81, the follower holder 83, the cam follower 84 and the cam surface 13A of the cam 13 are transmitted to the plunger 45.
The plunger advancing / retreating drive means 80 is constituted by the above.

The rotor 61 has a follower holder 83.
An opening 85 is formed for removing the pin when the rod is removed from the rod 81. Further, the cap 12 is formed with a drain port 19 used for discharging the leaked liquid and for cleaning the inside of the pump.

Next, the operation of this embodiment will be described.
Before operating the plunger pump 1 of the present embodiment, a tank for liquid to be transferred is connected to the suction port 21 via a tube or the like, and a transfer destination container is connected to the discharge port 22 via a tube or the like. . A liquid recovery tank is also connected to the drain port 19 via a tube or the like.

When the motor 65 of the rotation driving means 60 is driven in such a state, the output shaft 66 is rotated by the pump via the rotation driving means 60 including the coupling 67, the rotating body 61, the spring guide block 50 and the like. The pump block 40 is transmitted to the block 40 and is rotated in a state of being in sliding contact with the valve block 30.

With this rotation, the rod 81 inserted in the rotary body 61 rotates together with the rotary body 61, so that the cam follower 84 supported by the rod 81 via the follower holder 83 acts by the pressing spring 56. By cam surface 13
While being in contact with A, it moves back and forth along the axial displacement of the cam surface 13A. At this time, since the cam follower 84 is guided by the follower guide hole 61C of the rotating body 61 so as to move only in the axial direction, the rod 81 smoothly moves back and forth along the axial displacement of the cam surface 13A.

When the rod 81 is moved back and forth, the U-seal receiver 72,
It is transmitted to the plunger 45 via the spring receiver 55 and the like, and the plunger 45 moves forward and backward in the plunger insertion hole 42 of the pump block 40 in the axial direction. To move the plunger 45 forward and backward, by setting the shape of the cam surface 13A to an appropriate shape, at a position where the plunger 45 faces the suction port 21, a direction away from the suction port 21 side, that is, in FIG. Moved to the right. By the rightward movement of the plunger 45, a negative pressure is generated in the space formed on the left end side of the plunger insertion hole 42, and the negative pressure causes the liquid to be transferred through the suction port 21, the communication hole 31, and the groove 34. Is inhaled.

At the point where the movement of the plunger 45 to the right is completed, the plunger insertion hole 42 is displaced from the position of the groove 34 communicated with the suction port 32, and is located on the groove 35 side of the communication hole 32 of the discharge port 22. It will move toward. During this movement, since the cam surface 13A has a flat shape without axial displacement, the plunger 45 does not move in the axial direction and moves toward the groove 35 side while maintaining the same position. Moving.

When the plunger insertion hole 42 comes to a position where it communicates with the groove 35 on the discharge port 21 side, the cam follower 8 of the plunger advancing / retreating drive means 80 is acted by the action of the cam surface 13A.
4 is moved to the left in the figure, and with the movement of the cam follower 84, the plunger 45 is also moved to the left via the rod 81 and the like, and the sucked liquid is introduced into the plunger insertion hole 42 at the left end surface of the plunger 45. Extruded from the communication hole 3
It discharges into the discharge port 22 via 2.

The operation of ejecting the liquid by the plunger 45 is performed while the plunger insertion hole 42 communicates with the semicircular groove 35.
When the plunger insertion hole 42 comes to a position out of the groove 35, the movement of the plunger 45 in the axial direction is stopped. The stopped state of the plunger 45 is maintained until the plunger insertion hole 42 is again in the position of the groove 34 on the suction port 21 side by the action of the cam surface 13A.

In this way, when the plunger insertion hole 42 comes to the groove 34 side of the suction port 21 again, the cam surface 1
By the action of 3A, the plunger 45 is moved to the right again, and is moved to the suction action of sucking the liquid from the suction port 21, and the same action is repeated thereafter to rotate the pump block 40 in one plunger insertion hole 42. With each accompanying one rotation, liquid suction and discharge operations are performed one cycle.

The suction and discharge operations associated with the advance / retreat of the plunger 45 are similarly performed for each plunger insertion hole 42, as shown in FIG.
As can be seen from the two adjacent plunger insertion holes 42
During the suction or discharge operation, the groove 34
Since the two can be simultaneously communicated with the groove 35, the liquid sucked into each of the plunger insertion holes 42 or discharged from each of the plunger insertion holes 42 is continuously sucked or discharged to maintain a constant flow rate. It is like this.
Moreover, by appropriately setting the shape of the cam surface 13A, the total flow rate of the liquid sucked into or discharged from each of the plunger insertion holes 42 is always constant, so that there is no pulsation suction and suction. Discharge is possible.

In the operation of the plunger pump 1 as described above, the pump block 40 is biased toward the valve block 30 side by the disc spring 51 as a biasing means via the spring guide block 50, so that both sliding contact surfaces 33, 41 are formed. Are brought into contact with each other with a predetermined contact pressure. Due to this contact pressure, the two sliding contact surfaces 33, 41 formed with a predetermined surface roughness are sufficiently sealed.

Further, when sucking / discharging a liquid which is particularly likely to solidify, by pouring water, solvent or the like from one drain port 19 to the other drain port 19, solidification of the liquid at the seal portion is prevented. It When the liquid leaks from the seal 71 or the like, it is collected from the drain port 19.

According to this embodiment, the following effects can be obtained. That is, the communication holes 31 and 32 of the valve block 30 that are respectively communicated with the intake port 21 and the discharge port 22 of the port block 20 are sealed by the sliding contact surfaces 33 and 41 that are in sliding contact with the end surfaces in the direction orthogonal to the axis.
It can be sufficiently sealed without the need for rubber products such as O-rings. In particular, since each valve block 30 and pump block 40 are made of alumina ceramic which is a hard material, the biasing force of the disc spring 51 can be made relatively large, and the transfer fluid can be completely sealed.

Further, since each of the blocks 30 and 40 is made of a hard material, one of them is not scraped as in the conventional case, the durability performance is improved and it can be used for a long time. Further, conventionally, since the resin was scraped, it was necessary to control the biasing force applied to the pump block 40 in consideration of durability and sealing property. However, in this embodiment, since the durability is high, the disc spring 51 is attached. The pump 1 can be easily handled without the need to control the power very closely.

Further, since the blocks 30 and 40 are made of a hard material, the rotation resistance can be reduced as compared with the case where the resin and the hard material are slidably contacted with each other, the motor 65 can be downsized, and the rotation control can be easily performed. Can be done accurately. Furthermore, since each block 30, 40 is made of alumina ceramic which is a hard material, the pressure resistance performance can be improved as compared with the conventional case.
Therefore, the transfer fluid can be sent under high pressure, and a high-viscosity liquid, which was difficult in the past, can also be transferred.

Further, since the long groove 36 passing through the central portion of the valve block 30 is provided, even if dust or the like enters the central shaft portion which is the immovable portion of the pump block 40, it is discharged into the long groove 36. Adhesion between the sliding contact surfaces 33 and 41 does not deteriorate and reliable sealing can be achieved. Furthermore, since the radius from the central axis of the long groove 36 is made larger than the diameter from the central axis of the pump block 40 to the plunger insertion hole 42, the plungers are inserted by rotating the blocks 30 and 40 relatively. It is possible to cover the whole of the circular locus drawn by the hole 42, and it is possible to discharge dust and the like that have entered the portion other than the central axis into the groove 36, so that the sealing performance can be further improved.

A U-seal receiver 7 which is a secondary seal
2, U seal 73 to primary seal 71 and plunger 45
Since it is provided closer to the plunger advancing / retreating drive means 80 side than the pressing spring 56 for urging, the structure can be simplified and manufacturing cost can be reduced.

Further, since the convex seal 71 is biased by the pressing spring 56, sufficient sealing can be performed, and also from this point, the transfer fluid of this embodiment can be completely sealed.

Further, since the valve block 30 and the pump block 40 are each made of a hard material such as alumina ceramic, they are not deformed as in the case of using a conventional elastic resin, and the discharge amount is extremely high. It can be controlled with precision. Further, as described above, not only rubber products such as O-rings are not used, but the valve block 30 and the pump block 40 are made of alumina ceramics. Port block 20 made of Teflon, which has excellent properties
Since it is about the convex seal 71, the pump 1 having excellent chemical resistance can be provided, and the transfer fluid that can be handled is not limited.

By injecting water or a solvent through the drain port 19, it is possible to prevent the transferred fluid from solidifying at the seal portion, and the plunger 45 can be operated smoothly at all times.

Furthermore, the plunger 45 is formed separately from the rod 81, and the connecting pin 43 of the pump block 40 is only inserted into the connecting hole 52 of the spring guide block 50. If the mounting bolts to the cap 12 are removed, the valve block 30, the pump block 40, the seal 71, the plunger 45, the pressing spring 56, etc. will be attached to the body 1 together with the port block 20.
A valve block 3 that can be easily separated from 0 and is a wetted part
0, the pump block 40, etc. can be easily removed. As a result, it is possible to easily check the state of the clogging of the suction and discharge ports 21 and 22 and the sliding contact surfaces 33 and 41, the moving state of the plunger 45, and the cleaning and maintenance of these portions.

Further, if the cap 12 is removed, the spring guide block 50 can also be removed, and it is possible to easily check, wash and maintain the seals 16 and 73 which are secondary seals.

Further, since the forward / backward movement of the plunger 45 is uniquely set by the shape of the cam surface 13A of the cam 13 through the rod 81, the plunger 45 moves by setting the shape of the cam surface 13A appropriately. Can be accurately controlled, and accurate discharge without pulsation can be performed. Also,
Since the plunger pump 1 sucks and discharges the liquid in an amount proportional to the rotation amount of the output shaft 66 of the motor 65, the discharge amount can be accurately and easily controlled by providing a controller for controlling the motor 65. it can.

FIG. 5 shows a second embodiment of the present invention. The same or corresponding components as those of the first embodiment are designated by the same reference numerals, and the description will be omitted or simplified.
The plunger pump 100 of the present embodiment has one plunger insertion hole 42 and one plunger 45, and the linear actuator 8 that directly advances and retracts the plunger 45 via the U seal receiver 72 as the plunger advancing and retracting drive means 80.
6, and a motor 91 having a gear 90 that meshes with the teeth 58 formed on the outer circumference of the spring guide block 50 as the rotation driving means 60.

In this embodiment, a plunger insertion hole 42 is formed in the central axis of the pump block 40, and this insertion hole 42
The opening on the sliding contact surface 41 side is the communication hole 3 of the valve block 30.
It is bent in the middle so that it can communicate with 1, 32. Then, the motor 91 rotates the pump block 40 through the spring guide block 50 or reciprocally rotates the pump block 40 by a predetermined angle to connect the plunger insertion hole 42 to the communication hole 3.
The suction / discharge ports 21 and 22 are connected to each other, and the linear actuator 86 advances and retracts the plunger 45 to suck and discharge the transfer liquid.

In this embodiment as well, the same operational effects as those of the first embodiment can be obtained, and
There is also an advantage that the mechanism is simplified and the size can be further reduced by using only one plunger 45. In this embodiment, an air cylinder may be provided instead of the motor 91 and the pump block 40 may be reciprocally rotated by a predetermined angle. Further, it is preferable to provide a sensor for measuring the rotational position of the pump block 40 in order to ensure the communication between the plunger insertion hole 42 and the communication holes 31, 32.

The present invention is not limited to the above-described embodiments, but includes modifications and improvements as long as the object of the present invention can be achieved. For example, the valve block 30 and the pump block 40 are not limited to those made of alumina ceramic as in the above-mentioned embodiments, but may be made of ceramics of other materials such as silicon nitride, or made of metal such as cemented carbide.

Further, the number of the plungers 45 is not limited to three or one, but may be two or four or more, in short, as long as the transfer liquid can be sucked and discharged. Further, the plunger advancing / retreating drive means 80 is not limited to the configuration of each of the above-described embodiments, and the end face of the plunger 45 is directly connected to the cam 1
3 may be driven by contacting the cam surface 13A of the pump block 3. Further, a drive shaft driven directly by a cylinder or a servo motor provided in a portion that rotates integrally with the pump block 40, or via a rack, a pinion, or the like. May be provided to move the plunger 45 forward and backward, or a suitable actuator may be provided in a portion that does not rotate integrally with the pump block 40 as in the second embodiment, and an appropriate structure may be used. be able to.

Further, the rotation driving means 60 of the pump block 40 is not limited to the structure of each of the above-mentioned embodiments, but a gear or the like is attached to the outer periphery of the pump block 40, and the gear is driven by a motor to directly rotate the pump block 40. You may.
However, the convex seal 7 which is the plunger seal mechanism 70 should be rotated with the spring guide block 50 without rotating only the pump block 40 as in each of the above embodiments.
1 and the large diameter portion 42A of the plunger insertion hole 42 do not move relative to each other, which is advantageous in that the sealing performance is good. Also,
The suction port 21 and the discharge port 22 provided in the port block 20 are named in this way for convenience, and if the rotation direction of the pump block 40 is reversed, the suction port 21 side becomes the discharge port and the discharge port 22. The side serves as an intake port and is not limited by its name.

Further, the disc spring 51 as the urging means may be another type of spring, but the disc spring 51 has an advantage that a large urging force can be obtained in a small space. Further, as the motor 65, 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. Further, the shape and structure of the other parts are not limited to those in the above embodiment, and various modifications can be made.

The plunger pump of the present invention is not only used for a constant flow rate that keeps a constant flow rate for a predetermined time, but for example, the motor 65 is appropriately controlled to discharge the liquid in a predetermined pattern, or the predetermined liquid is discharged. It can be used when a small amount of liquid is discharged into the line for mixing according to the flow rate measurement value of the flowing line, or when sampling is performed from the line.

Furthermore, a plunger pump is interposed in a line in which a predetermined liquid is flowing, and the motor 65 is operated so that the pressures in the lines before and after the pump are in an equilibrium state. The flow rate may be measured from the number of pulses or the like. In particular, the plunger pump of the present invention is suitable for sucking / discharging a very small amount of liquid, and therefore can be used as an extremely minute flow meter.

[0062]

According to the present invention as described above, it is possible to provide a plunger pump which can suck and discharge a liquid with high accuracy, has high durability, and is easy to handle.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing an essential part of the first embodiment of the present invention.

FIG. 3 is a side view taken along the line III-III in FIG.

4 is a cross-sectional view taken along line IV-IV of FIG.

FIG. 5 is a sectional view showing a second embodiment of the present invention.

[Explanation of symbols]

 1,100 Plunger pump 10 Body 13 Cam 16 Seal 20 Port block 21 Suction port 22 Discharge port 30 Valve block 31,32 Communication hole 33,41 Sliding contact surface 34,35 Groove 36 Long groove 40 Pump block 42 Plunger insertion hole 45 Plunger 50 Spring guide block 51 Belleville spring as biasing means 56 Pressing spring as biasing member 60 Rotation drive means 61 Rotating body 70 Plunger seal mechanism 71 Convex seal 72 U seal receiver 73 U seal 80 Plunger advancing and retracting drive means 81 Rod 84 Cam follower 86 Linear actuator 91 motor

Claims (3)

[Claims] 1. A body, and a valve block which is attached to the body and has a sliding contact surface in which communication holes that communicate with the suction port and the discharge port are opened, respectively.
While being rotatably supported by the body in a state where one end of the sliding contact surface of the valve block is in contact with the sliding contact surface,
A pump block having a plunger insertion hole axially bored in a state of being communicable with the opening of the communication hole of the valve block; a biasing means for biasing the pump block toward the valve block; A rotary drive means for rotationally driving the block; and a plunger that is axially slidably inserted into a plunger insertion hole of the pump block,
While driving this plunger axially,
The plunger insertion hole of the pump block is driven in the suction direction with the plunger insertion hole communicating with the suction port through the communication hole, and the plunger insertion hole is communicated with the discharge port through the communication hole. A plunger advancing / retreating drive means for driving the plunger in the discharge direction and a plunger seal mechanism for sealing the plunger and the plunger insertion hole of the pump block are provided, and the valve block and the pump block are each formed of a hard material. Plunger pump characterized by that. 2. The plunger pump according to claim 1, wherein a recess is formed in at least a central portion of a sliding contact surface of the valve block. 3. The plunger pump according to claim 1 or 2, wherein a primary seal composed of a sliding contact surface of the valve block and the pump block, a plunger seal mechanism, and a liquid leaking from the primary seal A plunger pump provided with a secondary seal for preventing leakage to each driving means side.