JPH11190291A - Flow passage switching device of pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow quick suction even at a high position by miniaturizing a priming suction pump such as a fire engine. SOLUTION: A plurality of suction pumps 2a, 2b which are driven at the same time are connected to the suction side of a main pump 1 which needs priming, and switching valves 7a, 7b are arranged between the plurality of suction pumps 2a, 2b. The suction pumps 2a, 2b can be switched to a parallel or series connection by switching the switching valves 7a, 7b so that when pressure on the suction side of the pump 1 is higher than a preset value, the suction pumps 2a, 2b are connected in parallel, whereas when the pressure is lower than the set value, the suction pumps 2a, 2b are connected in series. The plurality of suction pumps 2a, 2b are arranged on the same drive shaft and are connected at their respective inlets to suction communicating pipes 4a, 4b and at their respective outlets to exhaust communicating pipes 5a, 5b. The suction communicating pipes 4a, 4b are connected to the exhaust communicating pipes 5a, 5b by a series communicating pipe 6, and the switching valves 7a, 7b are provided at the intersections of the communicating pipes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump which requires priming, and more particularly to a flow switching device for a pump (suction pump) for quickly supplying priming such as a fire fighting pump.

[0002]

2. Description of the Related Art Conventionally, pumps that require priming,
For example, when a spiral pump is applied to a fire pump, etc.,
In order to quickly supply and discharge water, a suction pump for priming is connected, and this suction pump needs to have a large capacity to absorb water as quickly as possible.In a rotary pump generally used as a suction pump, Larger outer diameters and longer overall lengths meet demand. However, when the outer diameter of the rotary pump is increased, the peripheral speed increases, the lubrication reaches its limit, and the inside is seized. In addition, if the total length is increased, the precision of machining becomes poor, and the machine cannot turn smoothly.

In such a case, a method of increasing the suction capacity by providing a plurality of suction pumps and connecting circuits for sucking the gas to be actuated in the water suction pipe in parallel is adopted. on the other hand,
When water is absorbed by a pump at a high position, it is required to lower the absolute pressure inside the water suction pipe. Therefore, a plurality of suction pumps are provided and circuits for sucking the gas to be actuated in the water suction pipe are arranged in series. The method has been adopted.

[0004]

Therefore, a conventional suction pump for priming a fire fighting pump is provided with a plurality of suction pumps connected in series to lower the absolute pressure in the suction pipe and to absorb water at a higher position. Further, the suction pump has a relatively large suction capacity so that a large amount of air in the water suction pipe is sucked so that water can be absorbed in a short time.
In this configuration, the capacity of each suction pump is increased, the outer diameter of the suction pump is increased, the weight is heavy, and the power required for driving is increased.

In a configuration in which a plurality of small priming suction pumps are provided and arranged in parallel in order to suck air in the pipe, the water absorption time can be shortened, but the absolute pressure in the pipe can be kept low. No water could be quickly absorbed by the suction pump arranged at a high place. An object of the present invention is to provide an inexpensive suction pump which eliminates such problems, has a short water absorption time, can generate a high vacuum, has a small diameter, is light, has a small driving force, and is inexpensive.

[0006]

In order to solve such a problem, the present invention connects a plurality of simultaneously driven suction pumps to the suction side of a main pump requiring priming, and A switching valve is arranged between the suction pumps so that the switching valve can be switched in parallel or in series.
When the pressure on the suction side is higher than a preset value, they are connected in parallel, and when they are lower than a preset value, they are connected in series. In addition, the plurality of suction pumps are arranged coaxially, the inlet of each suction pump is connected to an intake communication pipe, the outlet of each suction pump is connected to an exhaust communication pipe, and the exhaust communication pipe is connected to the exhaust communication pipe. The pipes were connected by serial communication pipes, and a switching valve was provided at the intersection of each communication pipe. The means for driving the switching valve uses a differential pressure between the atmospheric pressure and the pressure on the intake side. Further, a serial communication pipe connecting the switching valve, the intake communication pipe, and the exhaust communication pipe is provided between the adjacent suction pumps. Further, the switching valve is provided on one axis.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The problem to be solved by the present invention and the means for solving it are as described above. Next, the configuration of the embodiment shown in the attached drawings will be described. FIG. 1 is a circuit diagram of a water pump according to a first embodiment of the present invention, in which an air circuit including a priming suction pump is switched in parallel. FIG.
Is a circuit diagram in which the air circuits are switched in series. FIG. 3 is a circuit diagram of a second embodiment having switching means for the air circuit. FIG. 4 is a front view of two priming suction pumps incorporating a valve for switching the air circuit of the suction pump of the present invention. FIG. 5 is a sectional view taken along line AA of FIG.
FIG. 6 is a sectional view taken along line BB of FIG.

In FIG. 1, a main pump 1 is a fire pump composed of a centrifugal pump.
One end of the water absorption pipe 8 is connected to the water absorption port 15 of the first embodiment, and the other end of the water absorption pipe 8 is supplied to the water source 19. A water discharge pipe 16 is connected to the water discharge port 18 via a water discharge valve 14. A pressure sensor (pressure sensor) 3 is provided at an intermediate portion (suction side) of the water absorption pipe 8.
And the intake communication pipe 4 are connected. A priming valve 13 is interposed on the upstream side of the intake communication pipe 4, the downstream side branches off, and one intake communication pipe 4a is connected to the inlet of the first-stage priming suction pump 2a, and the other intake communication pipe 4b is Three-way switching valve 7a
Is connected to the inlet of the second-stage priming suction pump 2b. The suction pumps 2a and 2b are composed of rotary pumps (roller pumps, vane pumps, etc.)
Both suction pumps 2a and 2b are arranged on the same drive shaft and operated simultaneously. Further, it is also possible to connect with the drive shaft of the main pump 1 and drive them simultaneously.

The outlet of the first-stage suction pump 2a is connected to an exhaust communication pipe 5a and is connected to a three-way switching valve 7b. The outlet of the second-stage suction pump 2b is connected to the exhaust communication pipe 5b, the middle of the exhaust communication pipe 5b is branched, one end is connected to the three-way switching valve 7b, and the other end is connected to the exhaust pipe 17. An arm 9 is fixed to the valve body of each of the three-way switching valve 7a and the three-way switching valve 7b. The other end of the arm 9 has an arm 12 of a driving unit 11 which is operated by a command from the pressure sensor 3 via a link 10. Are rotatably connected to each other to constitute a flow path switching device. The driving means 11 is constituted by a motor, an electric cylinder, a solenoid, or the like.
In FIG. 1, the intake communication pipe 4a and the intake communication pipe 4b
Are communicated via the three-way switching valve 7a, and the exhaust communication pipe 5a
And the exhaust communication pipe 5b are communicated via the three-way switching valve 7b, and a flow path is formed in which the suction pump 2a and the suction pump 2b are arranged in parallel. The three-way switching valve 7
a and the remaining ports of the three-way switching valve 7 b are connected by a serial communication pipe 6. That is, the switching valves 7a and 7b are provided at the intersections of the intake communication pipes 4a and 4b, the exhaust communication pipes 5a and 5b, and the series communication pipe 6.
7b is arranged.

FIG. 2 shows a state in which the drive means 11 are operated. When the three-way switching valve 7a is switched, the serial communication pipe 6 and the second-stage suction pump 2b are switched.
And a three-way switching valve 7b
Is switched, the serial communication pipe 6 and the exhaust communication pipe 5a connected to the first-stage suction pump 2a communicate with each other,
A flow path is formed in which the suction pump 2a and the suction pump 2b are connected in series.

In such a configuration, the main pump 1
1 is operated at a relatively low position with respect to the water source 19, as shown in FIG. 1, when the priming valve 13 is opened and the priming suction pumps 2a and 2b are operated, the water suction pipe 8 and the intake communication pipe 4a are operated. In addition, since the air in the intake communication pipe 4b is sucked, and the air is exhausted from the exhaust communication pipe 5a and the exhaust communication pipe 5b through the exhaust pipe 17, the absolute pressure inside the intake communication pipe 4 decreases, and the water connected to the intake communication pipe 4 is absorbed. The absolute pressure inside the pipe 8 is also lower than the atmospheric pressure, and the water surface of the water source 19 is pushed to the atmospheric pressure, and the water rises inside the water absorbing pipe 8. In this state, the two suction pumps 2a and 2b are connected in parallel, so that the two suction pumps 2a and 2b work in parallel, and the suction communication pipe 4 and the water absorption pipe 8, which are a large amount of the affected gas, The air is sucked in, and water rises into the water suction pipe 8 quickly. Therefore,
The priming water is sent from the water suction pipe 8 to the suction side of the main pump 1, and the water discharge operation can be started through the water discharge pipe 16 by operating the main pump 1 and opening the water discharge valve 14.

On the other hand, the main pump 1
In the case where the suction pumps 2a and 2b are arranged at a position higher than the suction pumps, suction is first performed using a flow path in which the suction pumps 2a and 2b are arranged in parallel, as shown in FIG. When the pressure in the water suction pipe 8 is reduced by continuing suction and reaches a preset absolute pressure, the pressure sensor 3 detects the set pressure, and issues a drive instruction signal to the drive means 11, and the arm 12 It is turned. The arm 12
The three-way switching valve 7a and the three-way switching valve 7b are rotated via the link 10 and the arm 9 as shown in FIG. At this time, the air passes from the water suction pipe 8 through the intake communication pipe 4a, passes from the first-stage priming suction pump 2a to the series communication pipe 6 connected to the three-way switching valve 7b, and further passes from the three-way switching valve 7a to the intake communication pipe 4b. The exhaust gas is discharged to the outside from an exhaust pipe 17 connected to the exhaust communication pipe 5b through the second-stage priming suction pump 2b.

Therefore, since the air sucked by one suction pump 2a is sucked again, the absolute pressure inside the intake communication pipe 4 becomes lower than the set pressure, and the absolute pressure inside the water suction pipe 8 connected to the suction communication pipe 4 also decreases. As a result, the pressure difference between the absolute pressure inside the water suction pipe 8 and the atmospheric pressure increases, and water can be absorbed by the main pump 1 at a high position. Further, in such a circuit, all the air in the water suction pipe 8 is passed through the first-stage suction pump 2a. At this time, the absolute pressure of the intake air is already low to some extent, and the density of the air is low. For example, if the set value of the pressure sensor 3 is set to one half of the atmospheric pressure, and the suction pumps 2a have the same capacity, the exhaust air weight per stage becomes the same as in the parallel operation at the atmospheric pressure. Therefore, the suction pumps 2 arranged in series
There is no delay in the suction time by a.2b. When the main pump 1 is operated and the water discharge valve 14 is opened after the priming water reaches the main pump 1 in this manner, the water discharged from the water discharge port 18 is discharged to the outside through the water discharge pipe 16 to perform the water discharge work.

Next, the construction of the suction pump according to the second embodiment, in which the passage switching device is incorporated, will be described with reference to FIG.
FIG. 3 is a circuit diagram in which the priming suction pumps 2a and 2b are connected in series. The circuit configuration and operation are the same as in the first embodiment. The flow path switching device in the second embodiment includes a three-way switching valve 7
a and 7b are connected by a link or the like and are switched in conjunction with each other. A rod 25 of a differential pressure driving device 20 is connected via a link 10 to an arm 9 fixed to a valve body of the three-way switching valve 7b. The rod 25 is connected to the film body 21 that separates the atmosphere chamber 20a and the pressure receiving chamber 20b. The pressure intake port 22 of the pressure receiving chamber 20 b and the intake communication pipe 4 communicate with each other via a conduit 23. The arm 9 is urged by a return spring 24 in a direction in which the three-way switching valves 7a and 7b switch the circuit to the parallel side.

When the priming suction pumps 2a and 2b are operated in such a configuration, the three-way switching valves 7a and 7b are connected in parallel by the urging force of the return spring 24 while the absolute pressure inside the intake communication pipe 4 is relatively high. The connection has been switched, and the two suction pumps 2a and 2b work in parallel to suck a large amount of air and can absorb water in a short time when the water absorption height is low.

When pumping water at a high position, if the suction pumps 2a and 2b are continuously sucked in a parallel connection, the absolute pressure inside the suction communication pipe 4 becomes low. The absolute pressure in the pressure receiving chamber 20b of the differential pressure driving device 20 is reduced through the intake port 22. Since atmospheric pressure acts on the atmosphere chamber 20a side, the film body 21 is curved toward the pressure receiving chamber 20b as shown in FIG.
The rod 25 fixed to the membrane 21 is retracted against the return spring 24, and the link 10 connected to the other end of the rod 25
, The arm 9 is rotated, and the three-way switching valves 7 a and 7 b are switched in series by the rotation of the arm 9. Therefore, the effect of the present invention, that is, from parallel to series or from series to parallel can be changed by the differential pressure driving device 20 and the return spring 24 without providing a pressure detector, a complicated signal processing circuit, or a driving means.

Next, the configuration of the priming suction pumps 2a and 2b into which the flow path switching devices of the first and second embodiments can be incorporated will be described. As shown in FIGS. 4 to 6, the priming suction pumps 2 a and 2 b are provided on the same drive shaft 27, and a drive pulley 26 is fixedly provided at one end of the drive shaft 27 and is driven to rotate. In addition, the priming suction pumps 2a and 2a
b, a shaft 7c is arranged in a direction perpendicular to the drive shaft 27, and the three-way switching valve 7a and the three-way switching valve 7b are formed on a single shaft 7c. The arm 9 is fixed, and the three-way switching valve 7a
7b can be switched simultaneously. Further, between the priming suction pumps 2a and 2b, the serial communication pipe 6 forms a flow path bypassing the drive shaft 27, and the three-way switching valve 7 is provided.
Communication between a and 7b is possible.

The internal structure of the suction pump 2b is as follows.
As shown in FIG. 6, a rotor 28 is fixed on a drive shaft 27, a groove is formed in the outer periphery of the rotor 28 in a radial direction, and a vane 29 is slidably inserted into the groove. The tip is in sliding contact with the inner surface of the case 30. The axis of the case 30 and the axis of the drive shaft 27 are eccentrically arranged, and an intake communication pipe 4b and an exhaust communication pipe 5b are opened on both sides where the outer periphery of the rotor 28 contacts the inner periphery of the case 30.
The internal structure of the suction pump 2a is also the same as that of the suction pump 2b.
It has the same shape as.

In such a configuration, when the driving pulley 26 is rotationally driven by a driving device (not shown), the rotor 28 fixed to the driving shaft 27 is rotated and slidably inserted into the rotor 28. Vane 29 is suction pump 2
The space that is in sliding contact with the inner surface 30 and that is interposed between the outer periphery of the rotor 28, the inner surface of the case 30, and the vane 29 gradually increases with rotation, and air is sucked in from the intake communication pipe 4a (or 4b) and further rotated. And the air is confined, moved to the exhaust communication pipe 5a (or 5b) side, and discharged. Thus, the intake communication pipe 4a (or 4
A low absolute pressure can be generated on the b) side.

Therefore, the two priming suction pumps 2a and 2b can be driven only by rotating one drive shaft 27.
Further, a drive shaft 2 is provided between the priming suction pumps 2a and 2b.
Since the width of the bearing for holding 7 is required, a gap is inevitably formed between the priming suction pumps 2a and 2b. By installing the serial communication pipe 6 and two three-way switching valves 7a and 7b for intake and exhaust in this gap, these parts can be arranged without increasing the overall size, and the two three-way switching valves 7a
7b can be molded on one shaft 7c, and two valves can be easily linked.

When the arm 9 is operated to one side, the shaft 7c constituting the three-way switching valves 7a and 7b is rotated to communicate the intake communication pipe 4a and the intake communication pipe 4b, and simultaneously communicate with the exhaust. The pipe 5a communicates with the exhaust communication pipe 5b to form a flow path in which the suction pumps 2a and 2b are arranged in parallel. When the arm 9 is operated to the opposite side, the three-way switching valves 7a and 7b are switched, and the exhaust communication pipe 5a of the first-stage suction pump 2a is connected to the series communication pipe 6 via the three-way switching valve 7b, and the serial communication is performed. The other end of the pipe 6 is connected to the intake communication pipe 4a via the three-way switching valve 7a.
The exhaust communication pipe 5b of the suction pump 2b is communicated with the exhaust pipe 17 to switch to a flow path in which the suction pumps 2a and 2b are connected in series.

In this embodiment, an example of an eccentric rotary vane pump has been described. However, any type of suction pump may be used, and switching of two suction pumps is described. The number and the individual capacity are not limited as long as is a plurality. In addition, the use of the suction pump has been described by using the priming pump as an example, but the suction pump may be used for any purpose.

[0023]

According to the present invention, the following effects can be obtained by the configuration described above. That is, as in claim 1,
A plurality of suction pumps that are driven simultaneously are connected to the suction side of the main pump that requires priming, and a switching valve is arranged between the plurality of suction pumps, and can be switched in parallel or in series by switching the switching valve. With this configuration, the main pump can be switched depending on the case where the main pump is installed at a low position and a high position with respect to the water source, so that priming water can be quickly guided and discharged from the main pump.

Further, when the pressure on the suction side is higher than a preset value, the connection is made in parallel, and when the pressure on the suction side is lower than the set value, the connection is made in series.
For example, when the water absorption height is low, priming water can be pumped up to the pump in a short time in a flow path in which suction pumps are arranged in parallel. On the other hand, when the water absorption height is high, the priming water is pulled up to the middle of the pipe in the flow path in which the suction pumps are arranged in parallel up to halfway, and then switched to the flow path arranged in series,
Absolute pressure in the pipe can be further reduced, and water can be absorbed smoothly up to a high position. Therefore, unlike the conventional system, a plurality of suction pumps having a relatively large capacity are connected in series, and the size of the suction pump is large, the weight is heavy, the power required for driving is not required to be large, and the suction pump according to the present invention is not required. By using the flow path switching device for switching the flow paths, a small and light suction drive can be provided with a small power required for driving.

As described in claim 3, a plurality of suction pumps are arranged coaxially, the inlet of each suction pump is connected to an intake communication pipe, and the outlet of each suction pump is connected to an exhaust communication pipe. Then, by connecting the intake communication pipe and the exhaust communication pipe with a serial communication pipe and providing a switching valve at the intersection of each communication pipe, it is possible to drive a plurality of suction pumps using the same drive shaft, The cost can be reduced by using a simple configuration. By switching a plurality of suction pumps by switching a switching valve, the flow path can be switched between a parallel flow path and a serial flow path. Can be provided.

According to a fourth aspect of the present invention, there is provided a pressure detector for detecting the pressure on the intake side by using the pressure difference between the atmospheric pressure and the pressure on the suction side as the means for driving the switching valve. Without the need to provide a processing circuit for processing complex signals starting from the vessel or a driving means for receiving and driving the signals, the pressure inside the pipe can be detected mechanically, and the switching valve can be automatically switched to reduce costs. Can be achieved.

According to the fifth aspect of the present invention, the switching valve is provided between the adjacent suction pumps, so that the bearing for holding the drive shaft of the adjacent suction pump is arranged.
The inevitably provided gaps can be used, and without increasing the overall size of the suction pumps arranged adjacent to each other, a plurality of pumps can be integrated and easily arranged side by side with a fire pump or the like. be able to.

According to a sixth aspect of the present invention, a series communication pipe connecting the intake communication pipe and the exhaust communication pipe is provided between adjacent suction pumps, so that a bearing for holding a drive shaft of an adjacent suction pump is arranged. Therefore, the inevitably provided gap can be used, and the overall size of the suction pumps arranged adjacent to each other does not increase, and a plurality of pumps can be integrated.

Further, by providing the switching valve on one shaft, the switching valve on the intake side and the switching valve on the exhaust side of the plurality of suction pumps are provided on one shaft. The two valves can be easily interlocked, and even if the air circuits of a plurality of suction pumps are switched between parallel and series, the switching operation can be easily switched with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a water pump according to a first embodiment of the present invention in which an air circuit including a priming suction pump is switched in parallel.

FIG. 2 is a circuit diagram in which air circuits are switched in series.

FIG. 3 is a circuit diagram of a second embodiment having a pneumatic circuit switching means.

FIG. 4 is a front view of two priming suction pumps incorporating a valve for switching an air circuit of the suction pump of the present invention.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

FIG. 6 is a sectional view taken along line BB of FIG. 4;

[Explanation of symbols]

 2 Suction pump 4a ・ 4b Intake communication pipe 5a ・ 5b Exhaust communication pipe 6 Series communication pipe 7a ・ 7b Three-way switching valve 20 Differential pressure drive device 27 Drive shaft

Claims (7)

[Claims] A plurality of simultaneously driven suction pumps are connected to the suction side of a main pump requiring priming, and a switching valve is arranged between the plurality of suction pumps. A flow path switching device for a pump, which is configured to be switchable in series. 2. The pump according to claim 1, wherein when the pressure on the suction side is higher than a preset value, the connection is made in parallel, and when the pressure on the suction side is lower than the set value, the connection is made in series. Channel switching device. 3. A plurality of suction pumps are arranged coaxially, an inlet of each suction pump is connected to an intake communication pipe, and an outlet of each suction pump is connected to an exhaust communication pipe. The flow path switching device for a pump according to claim 2, wherein the exhaust communication pipe is connected to the exhaust communication pipe by a series communication pipe, and a switching valve is provided at an intersection of each communication pipe. 4. The apparatus according to claim 3, wherein the means for driving the switching valve uses a differential pressure between the atmospheric pressure and the pressure on the suction side.
A flow path switching device for a pump according to the above. 5. The pump flow switching device according to claim 3, wherein said switching valve is provided between adjacent suction pumps. 6. The pump flow switching device according to claim 3, wherein a series communication pipe connecting the intake communication pipe and the exhaust communication pipe is provided between adjacent suction pumps. 7. The flow path switching device for a pump according to claim 3, wherein the switching valve is provided on one axis.