JP2000199477A - Double piston pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double piston pump capable of discharging a fluid successively while suppressing pulsation generated in the discharged fluid. SOLUTION: A double piston pump is used to force feed a fluid with high viscosity and low fluidity. It is provided with a pair of the forced feed cylinder systems 1, 2, force feed pistons of which repeat fluid intake stroke and discharge stroke alternatively, and discharges the fluid successively. In the pressure cylinder system 1, 2, the total of a time required for the intake stroke and that required for switching from the intake stroke to the discharge stroke is relatively set shorter than the time required for the discharge stroke. The double piston pump is controlled so that either pressure cylinder system starts the discharge stroke upon deceleration of the discharge stroke in the other pressure cylinder system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double piston pump for continuously discharging a highly viscous and low fluidity fluid such as ready-mixed concrete or sludge.

[0002]

2. Description of the Related Art Conventionally, as a double piston pump,
For example, there is a poppet valve type double piston pump. As shown in FIG. 10, the double piston pump includes a pair of hydraulic cylinder devices 50 and 51 (cylinder device for pressure feeding) for alternately sucking and discharging a fluid, and a fluid supply unit (a hopper or the like: not shown). And a discharge pipe 53 for discharging the fluid to a transport pipe (not shown).
And the fluid pressure feed chamber 50 of each hydraulic cylinder device 50, 51
suction valves 54, 59 for switching the communication between the fluid cylinders 50, 51f and the suction port 52; and discharge valves 55, 56 for switching the communication between the fluid pressure chambers 50f, 51f of the hydraulic cylinder devices 50, 51.

That is, each of the above hydraulic cylinder devices 50,
51 is a single hydraulic cylinder tube 50a,
51a, two pistons 50b, 50c, 51b, 5
1c, and its two pistons 50b, 50c,
51b and 51c are respectively connected by piston rods. In the hydraulic cylinder devices 50 and 51, hydraulic chambers 50d and 50e are provided on both sides of the pistons 50b and 51b (hereinafter, referred to as drive pistons) on the right side in the figure.
51d and 51e (hereinafter referred to as driving chambers) are formed, and the driving chambers 50d, 50e, 51d and 51e, and the driving pistons 50b and 50c form respective driving cylinders.

The front drive chambers 50e and 51e communicate with each other through a communication passage 58, and the rear drive chambers 50d and 51d are connected to each other.
Are connected to the same hydraulic circuit 57 so that hydraulic pressure can be supplied alternately. Pistons 50c and 51 on the left side in the figure
c (hereinafter referred to as a pumping piston) front chambers 50f, 5f
1f constitutes a chamber (fluid pumping chamber) into which a fluid such as ready-mixed concrete flows.

[0005] The fluid pressure feed chambers 50f and 51f of the hydraulic cylinder devices 50 and 51 are respectively connected via suction valves 54 and 59 (suction switching means) and discharge valves 55 and 56 (discharge switching means) comprising poppet valves. It communicates with the same suction port 52 and discharge port 53. However, for each of the hydraulic cylinder devices 50, 51, one chamber of the switching cylinder that drives the suction valves 54, 59 and one chamber of the switching cylinder that drives the discharge valves 55, 56 communicate with each other.
The suction valves 54, 59 and the discharge valves 55, 56 are set so as to always open and close in synchronization with each other for each of the hydraulic cylinder devices 50, 51.

With the above arrangement, for example, when hydraulic pressure is supplied from the hydraulic circuit 57 to the rear drive chamber 50d of the one hydraulic cylinder device 50 and the piston 50c enters the discharge stroke, the front side of the one hydraulic cylinder device 50 becomes Is supplied to the front drive chamber 51e of the other hydraulic cylinder device, and the piston 51e of the other hydraulic cylinder device 51 performs a suction stroke.

As described above, in the conventional double piston pump, one hydraulic circuit 57 uses two rear drive chambers 50d,
By alternately supplying hydraulic pressure to 51d and connecting the front drive chambers 50e and 51e with each other through the communication pipe 58,
Each drive piston 50b, 51 of two drive cylinder parts
b, that is, the two pumping cylinders 50c and 51c advance and retreat in opposite directions at the same speed and synchronously.

That is, two hydraulic cylinder devices 50,
51, the suction stroke and the discharge stroke are always performed in synchronization, and the time required for the suction stroke and the discharge stroke is set to be the same.

[0009]

The conventional double piston pump as described above has a configuration in which one hydraulic circuit 57 alternately supplies hydraulic pressure to the rear drive chambers 50d, 51d. It has been difficult to individually control the suction and discharge strokes of 50 and 51. Also, as shown in FIG. 11, when one hydraulic cylinder device is in the discharge stroke, the other hydraulic cylinder device is in the suction stroke in synchronization with the discharge stroke, and the same as the discharge speed. Aspirating fluid at speed. By alternately repeating this, the fluid is continuously discharged.

For this reason, the pistons 50c, 51c
It is necessary to operate the suction valves 54, 59 and the discharge valves 55, 56 in an interlocked manner in a state in which the reciprocation of the suction port is stopped, and the communication between the discharge port 53 and the suction port 52 is switched (the swing pipe 6).
1 to switch the connection) (X in FIG. 11)
Part) is required. Due to this pause time, as shown in the waveform of the merged discharge amount from the piston pump shown in the lowermost stage in FIG. 11, the discharge amount of the fluid temporarily decreases sharply, and pressure pulsation occurs in the discharge of the fluid. Problem.

This pulsation causes whirling of the transport pipe for transporting the discharged fluid. The present invention has been made in view of the above problems, and provides a double piston pump capable of continuously discharging fluid while suppressing pulsation generated in the discharged fluid. It is an issue.

[0012]

In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is a double piston pump used for pumping a high-viscosity, low-flow fluid. A pump that includes a pair of pressure-feeding cylinder devices, wherein the pistons of the pair of pressure-feed cylinder devices alternately repeat a suction stroke and a discharge stroke of the fluid to continuously discharge the fluid. It is an object of the present invention to provide a double piston pump characterized in that each of the pressure feeding cylinder devices is driven by a separate hydraulic circuit.

According to the present invention, the discharge stroke and the suction stroke of each of the pressure-feeding cylinder devices can be individually controlled by driving the pair of pressure-feeding cylinder devices with individual fluid pressure circuits. , More precise control of discharge and suction is possible. Next, an invention according to claim 2 is a double piston pump used for pumping a high-viscosity, low-flow fluid, comprising a pair of pumping cylinder devices, and the pair of pumping cylinders. In a pump in which a piston of the device alternately repeats a suction stroke and a discharge stroke of a fluid and continuously discharges the fluid, in the pumping cylinder device, the time required for the suction stroke and the time required for the suction stroke to change from the discharge stroke to the discharge stroke. The total time with the time required for the switching is set relatively shorter than the time required for the discharge stroke, and the discharge stroke by the other pressure feeding cylinder device is completed before the discharge stroke by one pressure feeding cylinder device is completed. A double piston pump is provided, characterized in that it is started.

At this time, it is preferable to drive the pair of pressure-feeding cylinder devices by separate fluid pressure circuits, respectively, because the control is simplified. According to the present invention, by setting the total time of the time required for the suction stroke and the time required for switching from the suction stroke to the discharge stroke relatively shorter than the time required for the discharge stroke, During the discharge stroke of the piston of the pressure cylinder device, the suction stroke on the other pressure-feeding cylinder device side is completed, and it is possible to switch to the discharge stroke and shift to the discharge stroke or wait in the dischargeable state. .

By starting the discharge stroke by the other hydraulic cylinder device before the discharge stroke by one pressure cylinder device is completed, the discharge of the fluid from the pump is continuously stopped without stopping the discharge of the fluid from the pump. Pumping is performed. Here, the start of the discharge stroke by the other pressure-feeding cylinder device is preferably at the time when the discharge stroke by the other pressure-feeding cylinder device approaches the stroke end and the discharge speed starts to be reduced.

In this way, even if the two-pressure feeding cylinder device is in the discharge stroke, the temporary increase in the total discharge amount is minimized, and the pulsation of the discharged fluid is minimized. it can.

[0017]

Next, a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the double piston pump of the present embodiment includes a pair of hydraulic cylinder devices 1 and 2 (cylinder device for pressure feeding), and chambers 1b on both sides of the right driving pistons 1a and 2a in FIG. , 1c,
2b, 2c (referred to as first drive chambers 1b, 2b and second drive chambers 1c, 2c, respectively), and the drive pistons 1a,
A drive cylinder portion is formed by 2a, and pistons 1a and 2a advance and retreat by hydraulic pressure supplied to the two drive chambers 1b, 1c, 2b and 2c, and a suction stroke and a discharge stroke are performed.

The fluid pressure supply chambers 1e, 2e formed before the left pressure supply pistons 1d, 2d communicate with one common suction port 3 and one common discharge port 4. The suction port 3 is connected to a hopper or the like (not shown) into which a high-viscosity, low-flow fluid such as ready-mixed concrete is charged, and the discharge port 4 communicates with a transport pipe (not shown) for transporting the fluid. ing.

Each of the fluid pressure feed chambers 1e, 2e and the discharge port 4
And a pair of discharge valves 5 and 6 (discharge switching means) for opening and closing a communication path with the discharge valve. Each of the discharge valves 5, 6 is constituted by a poppet valve operated by a hydraulic cylinder. Further, separate suction valves 7, 8 (suction switching means) for individually opening and closing the passages with the suction port 3 are provided for each of the fluid pressure supply chambers 1e, 2e. These two suction valves 7, 8 are also constituted by poppet valves operated by hydraulic cylinders.

The hydraulic circuits P1 and P2 for operating the pair of discharge valves 5 and 6 and the pair of suction valves 7 and 8 are independent of the hydraulic cylinder devices 1 and 2, respectively. One discharge valve 5 and one suction valve 7 are connected to one switching valve hydraulic pump 29 via individual directional control valves 9 and 10 (electromagnetic switching valves) to form a hydraulic circuit. The discharge valve 5 and the suction valve 7 are controlled by two directional control valves 9 and 10.
Are controlled to open and close in synchronization or individually.

The positions of the two directional control valves 9 and 10 are individually switched by a command from a controller (not shown). Reference numeral 11 denotes a relief valve that protects each hydraulic device except for abnormal pressure rise in the circuit. The hydraulic circuit P2 for the discharge valve 6 and the suction valve 8 of the other hydraulic cylinder device 2 has the same configuration. Reference numerals 12 and 13 represent directional control valves, and reference numeral 14 represents a switching valve hydraulic pump.

The stroke end of each piston in the switching cylinder devices 15 to 18 for operating the discharge valves 5 and 6 and the suction valves 7 and 8, that is, opening and closing by the discharge valves 5 and 6 and the suction valves 7 and 8. , Limit switches LS7 to LS14 (proximity switches)
And the limit switches LS7 to LS1
4 is controlled based on the detection signal.

In the present embodiment, each of the drive chambers 1b, 1c,
Drive hydraulic circuits P3 and P4, which are fluid pressure circuits for supplying oil pressure to 2b and 2c, are also independent for each of the hydraulic cylinder devices 1 and 2 and are supplied from two individual double swing hydraulic pumps 19 and 20. The drive pistons 1a and 2a are independently advanced and retracted by the pressure oil.

Since the constructions of the two drive hydraulic circuits P3 and P4 are the same, the following description focuses on one drive hydraulic circuit P3, and the other drive hydraulic circuit P4 has the same reference numeral. The description is omitted. The drive hydraulic circuit P3 includes two drive chambers 1 sandwiching the drive piston 1a.
b and 1c are connected to the swing hydraulic pump 19 through separate first and second oil passages 21 and 22 so that pressure oil is supplied from the swing hydraulic pump 19 to the respective drive chambers 1b and 1c. Has become. Further, a bypass oil passage 23 is provided between the first oil passage 21 and the second oil passage 22, and returns from the drive chambers 1 b and 1 c through a pilot switching valve 24 inserted in the bypass oil passage 23. An oil passage is formed.
The relief valve denoted by reference numeral 25 is for maintaining the pressure in the drive chambers 1b and 1c on the side to which the pressure oil is not supplied from the swing hydraulic pump 19 at a predetermined pressure or higher. In addition, an auxiliary pump 26 for pressure compensation is provided to prevent a pressure drop at the time of switching of the discharge of the swing hydraulic pump 19 and the like, thereby suppressing a delay in operation.

The discharge directions and discharge pressures of the two double swing hydraulic pumps 19 and 20 are controlled by a controller. Each hydraulic cylinder device 1, 2 has a piston 1 d,
Limit switches LS1 to LS6 (proximity switches) are provided for detecting that 2d has reached the stroke end position and the deceleration point near the stroke end in the discharge stroke, respectively.

The controller controls each of the limit switches LS
1 to LS14, the phases of fluid discharge and suction by the two hydraulic cylinder devices 1 and 2 are shown in FIG.
Directional control valves 9, 10, 1 so that the phases shown in FIG.
2, 13 and the swing hydraulic pumps 19, 20 to individually control the suction stroke and the discharge stroke of each piston 1d, 2d.

Here, the discharge pressure of each of the double-swing hydraulic pumps 19, 20 is controlled by the two drive chambers 1b,
From the controllers 1c, 2b, and 2c, the controller sets the flow rate when supplying the pressurized oil to the second drive chambers 1c and 2c larger than when supplying the pressurized oil to the first drive chambers 1b and 2b. By giving commands to the swing hydraulic pumps 19 and 20,
The time required for the discharge stroke is adjusted to be relatively longer than the total time required for the suction stroke and the time required for switching from the suction stroke to the discharge stroke in the hydraulic cylinder devices 1 and 2.

In the present embodiment, each swing hydraulic pump 1
The tilt angles 9 and 20 are controlled by determining and adjusting whether the stroke is the discharge stroke or the suction stroke. The control procedure will be described with reference to FIGS. Hydraulic cylinder device 2 on the discharge stroke side
Side (the B cylinder side in the figure)
Has reached the deceleration point and the limit switch LS
6, when the suction stroke is completed and the switching to the discharge stroke is completed, the other hydraulic cylinder device 1 side (A hydraulic cylinder side in the figure) is instructed to the direction control valve 9 to open the discharge valve 5. Then, the swing hydraulic pump 19 is tilted, and the pressure-feeding piston 1d of the other hydraulic cylinder device 1 is moved.
Is a discharge stroke (stroke 1, see FIG. 3A).

Next, the limit switch L indicates that the pressure-feeding piston 2d has further advanced and reached the end position of the discharge stroke.
When S5 is detected (stroke 2, see FIG. 3 (b)), a command is given to the direction control valve 12 on the hydraulic cylinder device 2 side to close the discharge valve 6, and subsequently, a command is given to the direction control valve 13 to perform suction. The valve 8 is opened to switch from the discharge stroke to the suction stroke. Then, the swing hydraulic pump 20 is tilted to
Let d be the suction stroke (stroke 3, see FIG. 3 (c)). At this time, the pressure-feeding piston 1d of the hydraulic cylinder device 1 is in a steady state in the discharge stroke.

As described above, the pressure-feeding piston 1d is in the discharge stroke and the pressure-feeding piston 2d is in the suction stroke. The speed of the pressure-feeding piston 2d in the suction stroke is higher than the speed of the pressure-feeding piston 1d in the discharge stroke. , The tilt angles of the swing hydraulic pumps 19 and 20 are controlled (stroke 4, FIG. 3).
(D)). Next, the limit switch LS indicates that the pressure-feeding piston 2D has retracted and has reached the end position of the suction stroke.
4 is detected (stroke 5, see FIG. 3 (e)), the direction control valve 13 is commanded to close the suction valve 8 on the pressure feeding piston 2d side, and then the discharge valve 6 is opened to switch to the discharge stroke and wait. State. At this time, the pressure feeding piston 1d is in a steady state in the discharge stroke.

Next, in the hydraulic cylinder device 1, when the limit switch LS3 detects that the pressure-feeding piston 1d has moved forward and reached the deceleration point, a command is issued to the direction control valve 12 for the hydraulic cylinder device 2 and the discharge valve is controlled. 6, the swing hydraulic pump 20 is tilted, and the pumping piston 2d is set to the discharge stroke (stroke 6, see FIG. 4A).

Next, the limit switch LS determines that the pressure-feeding piston 1d has advanced and reached the end position of the discharge stroke.
4 is detected (stroke 7, see FIG. 4 (b)), a command is given to the direction control valve 9 on the hydraulic cylinder device 1 side, and the discharge valve 5
, And then instructs the direction control valve 10 to open the suction valve 7 to switch from the discharge stroke to the suction stroke.
The swing hydraulic pump 19 is tilted, and the pressure feeding piston 1d is set to the suction stroke (stroke 8, see FIG. 4C). At this time, the pressure-feeding piston 2d is in a steady state in the discharge stroke.

As described above, the pressure-feeding piston 2d is in the discharge stroke and the pressure-feeding piston 1d is in the suction stroke. The speed of the pressure-feeding piston 1d in the suction stroke is higher than the speed of the pressure-feeding piston 2d in the discharge stroke. , The tilt angles of the swing hydraulic pumps 19 and 20 are controlled (stroke 9, FIG. 4).
(D)). Next, the limit switch LS indicates that the pressure-feeding piston 1d has retracted and has reached the end position of the suction stroke.
When 1 is detected (stroke 10, see FIG. 4 (e)), the direction control valve 10 is commanded to close the suction valve 7 on the side of the pressure feeding piston 1d. At this time, the pressure-feeding pistons 1d and 2dB are in a steady state in the discharge stroke.

Then, the process shifts again to the control of the above-mentioned step 1. The controller repeats the control so as to perform the above series of steps, as shown in the lowermost row in FIG.
Fluctuation (pulsation) of the discharge amount from the double piston pump is suppressed, and continuous continuous pressure feeding becomes possible. In the present embodiment, the hydraulic circuits P3 and P4 for driving the hydraulic cylinder devices 1 and 2 are individually provided, and both front drive chambers 1 and 2 are disposed.
Since the cylinders c and 2c operate independently without communicating with each other, the suction and discharge by the hydraulic cylinder devices 1 and 2 can be individually controlled. For example, the continuous discharge state as described above Can be realized.

Here, the two drive cylinders are driven by separate hydraulic circuits P3 and P4, but may be controlled by one hydraulic circuit so as to perform the above-described suction and discharge strokes. However, the hydraulic circuit becomes complicated. Next, a second embodiment will be described with reference to the drawings. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The double piston pump according to the present embodiment is an example in which an oscillating tube is employed for switching between suction and discharge. The driving cylinder portions of the pair of hydraulic cylinder devices 1 and 2 are, as shown in FIG. 5, similar to the first embodiment,
It is driven by individual drive hydraulic circuits P3 and P4. The end openings of the fluid pressure supply chambers 1e and 2e communicate with suction and discharge ports 31 and 32 (see FIG. 6) provided in a hopper 30 containing a highly viscous fluid such as ready-mixed concrete, respectively. The fluid can be sucked from 30.

In this embodiment, rocking tubes 33 and 34 are individually provided for each end opening. The rear ends of the swinging pipes 33 and 34 are connected to the Y-shaped pipe 35 so that the discharge of the fluid merges. The tip opening sides of the rocking tubes 33 and 34 are respectively provided with rocking shafts 33a and 33a.
Left and right can be swung around 34a, and by operating the individual switching cylinders 36 and 37, they face and communicate with the end openings of the fluid pressure feed chambers 1e and 2e. Reference numerals 38, 38 denote directional control valves for controlling the switching cylinder.

Further, plate-like sealing members 40 and 41 are provided in the swinging directions Y and Z on the sides of the tip openings of the swinging tubes 33 and 34.
Is overhanging. Thereby, the fluid pressure feed chambers 1e, 2
When the swing tubes 33 and 34 swing, the end opening of e
During the transition from the communication state (discharge state) to the oscillating pipes 33, 34 to the hopper communication state (suction state), the seal members 40, 41 face the end openings of the fluid pressure feed chambers 1e, 2e. And the fluid pressure feed chambers 1e and 2e are in non-communication from both the hopper 30 and the swinging pipes 33 and 34.

Limit switches LS7 to LS7 for detecting the swinging position of the opening at the tip of each of the swinging tubes 33 and 34.
S10 is provided, and each of the limit switches LS7 to LS1
0 indicates that the detection signal can be supplied to a controller (not shown) when the distal end openings of the oscillating tubes 33 and 34 reach the detection position. The controller performs control similar to that of the controller of the first embodiment to realize the discharge stroke and the suction stroke in each of the hydraulic cylinder devices 1 and 2 shown in FIG.

The control procedure will be described with reference to FIGS. When the limit switch LS6 detects that the pressure-feeding piston 2d moves forward and reaches the deceleration point on the hydraulic cylinder device 2 side (B cylinder side in the drawing) on the discharge stroke side, the hydraulic cylinder device 1 side (A hydraulic pressure in the drawing) With respect to the cylinder side), the switching cylinder 36 is instructed to communicate the oscillating pipe 33 with the fluid pressure feeding chamber 1e, and then the swinging hydraulic pump 19 is tilted to move the pressure feeding piston 1d of the hydraulic cylinder device 1 to the discharge stroke. (Stroke 1, FIG. 7 (a) and FIG.
(See (a)).

Next, the limit switch L indicates that the pressure-feeding piston 2d has further advanced and reached the end position of the discharge stroke.
When S5 is detected (stroke 2, see FIG. 7 (b)), a command is issued to the switching cylinder 37 on the hydraulic cylinder device 2 side to swing the swinging pipe 34, thereby allowing the fluid pressure feed chamber 2e to communicate with the hopper 30. Subsequently, the swing hydraulic pump 20 is tilted, and the pressure feeding piston 2d is set to the suction stroke. In addition, the pressure feed piston 1d
Is in a steady state of the discharge stroke. (Step 3, Fig. 7
(C) and FIG. 9 (c)).

At this time, as the swinging tube 34 swings, the state changes from (a) to (b) to (c) in FIG. 9, and due to the presence of the seal member 41, the liquid pressure feeding chamber 2e is It is avoided that the fluid communicates with both the hopper 30 and the oscillating tube 34, and the discharge fluid from the oscillating tube 33 is prevented from flowing back to the hopper 30 through the oscillating tube 34 and the fluid pressure chamber 2e. You can see that.

As described above, the pressure-feeding piston 1d is in the discharge stroke and the pressure-feeding piston 2d is in the suction stroke. The speed of the pressure-feeding piston 2d in the suction stroke is higher than the speed of the pressure-feeding piston 1d in the discharge stroke. The tilt angle of the swing hydraulic pumps 19, 20 is controlled (stroke 4, FIG. 7).
(D)). Next, in the hydraulic cylinder device 1, when the limit switch LS3 detects that the pressure-feeding piston 1d has moved forward and reached the deceleration point, a command is issued to the switching cylinder 37 of the hydraulic cylinder device 2 to swing the fluid pressure-feeding chamber 2e. After communicating with the pipe 34, the double swing hydraulic pump 20 is tilted, and the pumping piston 2d is set to the discharge stroke (see stroke 6, FIGS. 8 (a) and 9 (e)).

Next, the limit switch LS2 indicates that the pressure-feeding piston 1d has moved forward and reached the end position of the discharge stroke.
Is detected (stroke 7, see FIG. 8 (b)), a command is issued to the switching cylinder 36 on the hydraulic cylinder device 1 side and the swing pipe 33 is
To make the fluid pressure feeding chamber 1e communicate with the hopper 30, switch from the discharge stroke to the suction stroke, and further tilt the hydraulic pump 19 to make the pressure feeding piston 1d the suction stroke (stroke 8, FIG. 8). (C)). At this time, the pressure-feeding piston 2d is in a steady state in the discharge stroke.

As described above, the pressure-feeding piston 2d is in the discharge stroke and the pressure-feeding piston 1d is in the suction stroke. The speed of the pressure-feeding piston 1d in the suction stroke is higher than the speed of the pressure-feeding piston 2d in the discharge stroke. The tilt angle of the swing hydraulic pumps 19, 20 is controlled (stroke 9, FIG. 8).
(D)). Next, when the limit switch LS1 detects that the pressure-feeding piston 1d has retracted and has reached the end position of the suction stroke (stroke 10, see FIG. 8 (e)), a command is issued to the switching cylinder 36 to cause the swing pipe 33 and the fluid to flow. The pumping chamber 1e is communicated.

Then, the process shifts again to the control of the stroke 1. The controller repeats the control so as to perform the above series of steps, as shown in the lowermost row in FIG.
Fluctuation (pulsation) of the discharge amount from the double piston pump is suppressed, and continuous continuous pressure feeding becomes possible. Also,
In all the above embodiments, the configuration of each of the hydraulic circuits P1 to P4 is not limited to the above configuration, and another hydraulic circuit configuration may be adopted.

Other functions and effects are the same as those of the first embodiment.

[0048]

As described above, when the present invention is adopted, suction and discharge by one pumping cylinder device can be controlled independently for each pumping cylinder device, and the entire pump can be more finely controlled. There is an effect that the suction and the discharge can be controlled. Further, when the invention described in claim 2 is adopted, there is an effect that a highly viscous and low fluidity fluid such as ready-mixed concrete can be continuously discharged in a low pulsation state.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a double piston pump according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a suction stroke, a discharge stroke, and a discharge amount of a pump in the two hydraulic cylinder devices according to the embodiment of the present invention.

FIGS. 3A and 3B are diagrams showing each step according to the first embodiment of the present invention, wherein FIG. 3A shows step 1; FIG. 3B shows step 2;
(C) shows step 3, (d) shows step 4, and (e) shows step 5.
, Respectively.

FIGS. 4A and 4B are diagrams showing each step according to the first embodiment of the present invention, wherein FIG. 4A shows step 6, FIG.
(C) shows step 8, (d) shows step 9, and (e) shows step 1.
0 is respectively represented.

FIG. 5 is a configuration diagram showing a double piston pump according to a second embodiment of the present invention.

FIG. 6 is a view showing a swing tube and a seal member according to a second embodiment of the present invention.

FIGS. 7A and 7B are diagrams showing each step according to the second embodiment of the present invention, in which FIG. 7A shows step 1, FIG.
(C) shows step 3, (d) shows step 4, and (e) shows step 5.
, Respectively.

FIGS. 8A and 8B are diagrams showing each step according to the second embodiment of the present invention, wherein FIG. 8A shows step 6, FIG.
(C) shows step 8, (d) shows step 9, and (e) shows step 1.
0 is respectively represented.

FIG. 9 is a diagram showing each step according to the second embodiment of the present invention, wherein (a) shows step 1 and (b) shows step 2;
(C) shows step 3, (d) shows step 4, and (e) shows step 5.
, Respectively.

FIG. 10 is a configuration diagram showing a conventional double piston pump.

FIG. 11 is a diagram showing a suction stroke, a discharge stroke, and a discharge amount of a pump in both hydraulic cylinder devices in the related art.

[Explanation of symbols]

Hydraulic circuit for switching P1, P2 P3, P4 Hydraulic circuit for driving LS1 to LS6 Limit switch for detecting piston position LS7 to LS14 Limit switch for detecting valve position X Pause time position Y, Z Swing direction 1 Hydraulic cylinder device ( A cylinder: pumping cylinder device) 1a drive piston 1b first drive chamber 1c second drive chamber 1d pumping piston 1e fluid pumping chamber 2 hydraulic cylinder device (B cylinder: pumping cylinder device) 2a drive piston 2b first drive chamber 2c 2nd drive chamber 2d pressure feed piston 2e fluid pressure feed chamber 3 suction port 4 discharge port 5 discharge valve 6 discharge valve 7 suction valve 8 suction valve 9-13 direction control valve 15-18 switching cylinder 19,20 double swing hydraulic pump 21, 22 first and second oil passages 24 electromagnetic pilot valve 30 hopper 31 32 suction discharge ports 33, 34 Yuradokan 35 Y-shaped tube 36, 37 switching cylinder 40, 41 seal member

Claims (2)

[Claims] 1. A double-piston pump used for pumping a high-viscosity, low-flow fluid, comprising a pair of pumping cylinder devices, wherein the pistons of the pair of pumping cylinder devices alternate with each other. A double-piston pump in which a pump that continuously discharges the fluid by repeating a suction stroke and a discharge stroke of the fluid, wherein the pair of pressure-feeding cylinder devices are driven by separate hydraulic circuits. 2. A double-piston pump used for pumping a high-viscosity, low-flow fluid, comprising a pair of pumping cylinder devices, wherein the pistons of the pair of pumping cylinder devices alternate with each other. In a pump that continuously discharges the fluid by repeating the suction stroke and the discharge stroke of the fluid, a total of a time required for the suction stroke and a time required for switching from the suction stroke to the discharge stroke in the compression cylinder device. The time is set relatively shorter than the time required for the discharge stroke, and the discharge stroke by the other pressure transfer cylinder device is started before the discharge stroke by the other pressure transfer cylinder device is completed. Double piston pump.