Automatic stop device and siphon-type liquid transfer pump with automatic stop device

Abstract

The present invention provides an automatic stop device that simplifies the structure, improves the responsiveness and reliability of stopping fluid delivery, and enables rapid stopping of fluid delivery in emergencies, as well as a siphon-type fluid delivery pump equipped with this automatic stop device. [Solution] The device includes a float 212 that detects the liquid level in the container to which the liquid is being delivered, and a storage section 213 that houses the float and holds air. A communication hole 214 is opened at the top of the storage section, and the held air is sent to the discharge valve 14 of the pump 1 via an air inlet tube 215. A slide valve 211 that operates in response to the float rising connects the top of the storage section and the air inlet tube via the communication hole when the float rises to a predetermined position. As a result, the discharge valve is closed by the released air, the liquid flow in the discharge hose 15 is restricted, and the liquid delivery of the siphon-type liquid delivery pump is stopped. This provides an automatic stop device 2 and a siphon-type liquid delivery pump having an automatic stop device.

Description

Technical Field

[0001] The disclosure in this specification relates to an automatic stop device and a siphon type liquid delivery pump having the automatic stop device.

Background Art

[0002] Conventionally, as a device for transferring a liquid such as kerosene to a container, a siphon type liquid delivery pump utilizing a siphon action has been widely known (typically referred to as a fuel supply pump or a kerosene pump). In this type of pump, in order to automatically stop the liquid delivery when the liquid delivery amount reaches a predetermined amount, an automatic stop mechanism for releasing the siphon action based on the operation of a float has been proposed. For example, a configuration is known in which an air vent hole or an air escape cap is opened as the float rises, and air is introduced into an air inlet tube to release the siphon action (see, for example, Patent Document 1 and Patent Document 2).

[0003] In these conventional technologies, an air inlet tube is connected to an air hole provided above the pump section, and a configuration for releasing the siphon action by opening and closing the air hole is adopted.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the devices according to the above-mentioned conventional technologies had the following problems.

[0006] Firstly, in a configuration where the air inlet pipe is connected to the air vent at the top of the working cylinder (pump), the air inlet path is long and the flow path tends to be complex, which can delay the release of the siphon effect and result in insufficient responsiveness to stopping the fluid supply. As a result, it was difficult to immediately stop the fluid supply in emergencies where the fluid supply volume was likely to become excessive.

[0007] Secondly, conventional technologies often employ a structure that combines multiple components such as air relief caps, valve bodies, and linkage mechanisms, resulting in a complex overall structure, an increase in the number of parts, and increased assembly time. This leads to higher manufacturing costs and a higher likelihood of malfunctions and failures.

[0008] Thirdly, in the conventional configuration, air for automatic stopping is introduced on the operating cylinder side. As with typical liquid transfer pumps that do not have an automatic stopping mechanism, the actions of the discharge valve and suction valve have an effect, and as a result, liquid remains in the discharge hose after the automatic stopping device is activated, which could lead to liquid spillage and a decrease in safety.

[0009] The present invention has been made in view of the above problems, and aims to provide an automatic stop device that can simplify the structure, improve the responsiveness and reliability of stopping liquid delivery, and quickly stop liquid delivery even in emergencies, and a siphon-type liquid delivery pump having an automatic stop device. [Means for solving the problem]

[0010] In order to resolve the above issues, one embodiment of the automatic stop device disclosed herein is: A float is positioned on the discharge port side of the discharge hose of a siphon-type liquid transfer pump, and in the container to which the liquid is being transferred, it rises as the liquid level increases, thereby detecting the liquid level. A storage section that houses the float, has an opening at the bottom that allows the liquid to enter as the liquid level rises, holds air above the float, and guides the float in the direction of buoyancy, Inside the aforementioned storage compartment, a slide valve is positioned above the float in the direction of its upward movement and operates in accordance with the float's upward movement. The cavity formed in the slide valve, The aforementioned storage section includes a support portion for the slide valve having a guide hole for guiding the operation of the slide valve, The support portion has a communication hole that connects the guide hole and the outside of the storage portion, It has an air inlet tube, one end of which is connected to the communication hole, and the other end of which is installed inside the discharge hose at a position facing the discharge valve interposed between the discharge hose and the operating cylinder of the siphon-type liquid transfer pump, In the state before the float rises, the communication hole is closed and the valve is shut in the portion where the cavity of the slide valve is not formed, and the slide valve, The above storage unit is inserted through a guide hole that penetrates from the upper surface on the support side, passing through the communication hole, In response to the float rising, it operates along the guide hole, It moves so as to protrude directly upward from the upper surface, When the cavity overlaps the communication hole, the valve opens, and the air held on the upper side of the storage section is released from the other end of the air inlet tube to close the discharge valve, thereby restricting the liquid flow in the discharge hose and stopping the liquid supply from the siphon-type liquid transfer pump.

[0011] With this configuration, the airflow can be controlled with a single valve (slide valve).

[0012] To resolve the above issues, one embodiment of a siphon-type liquid transfer pump disclosed herein is equipped with the automatic stop device. [Effects of the Invention]

[0013] The automatic stop device and the siphon-type liquid transfer pump equipped with the automatic stop device of the present invention are configured to connect the air inlet tube to the discharge valve side, thereby allowing air to be directly introduced to the siphon-type liquid transfer pump (discharge hose) side. This allows for good control of the airflow and ensures that the discharge valve is closed reliably and quickly, thereby quickly releasing the siphon action and immediately stopping the refueling.

[0014] In addition, since an automatic stop mechanism can be realized with a relatively simple configuration without requiring an air escape cap or a complicated link mechanism as in the prior art, the number of parts can be reduced, the assembly property can be improved, and the manufacturing cost can be lowered.

[0015] Since the discharge valve is closed when the fuel supply stops, it is difficult for the liquid to remain in the fuel supply pipe, the spillage of the liquid can be prevented, and the safety can be improved.

[0016] In addition, the automatic stop device of the present invention and the siphon type liquid feeding pump having the automatic stop device are configured to stop the liquid feeding by the operation of the float and the inflow of air without using a battery or electronic components, so the risk of failure is low and stable operation can be maintained over a long period of time. It has such an effect.

Brief Description of Drawings

[0017] [Figure 1] FIG. 1 is a side cross-sectional view of a siphon type liquid feeding pump equipped with an automatic stop device. [Figure 2] FIG. 2 is a schematic top view of the installation configuration of the slide valve of the automatic stop device. [Figure 3] FIG. 3 is a schematic side view of the installation configuration of the slide valve of the automatic stop device. [Figure 4] FIG. 4 is a schematic side view (modified example) of the installation configuration of the slide valve of the automatic stop device. [Figure 5] FIG. 5 is a schematic side view of the installation configuration of the float. [Figure 6] FIG. 6 is a schematic diagram partially enlarging the attachment portion of the air inflow tube. [Figure 7] FIG. 7 is a schematic diagram showing the closed state of the slide valve. [Figure 8] FIG. 8 is a schematic diagram showing the open state of the slide valve. [Figure 9] FIG. 9 is a side view of a siphon type liquid feeding pump with the automatic stop device externally mounted. [Figure 10]Figure 10 is a side view of a siphon-type liquid transfer pump with an extended air inlet tube of a slide valve enclosed with an automatic stop device. [Modes for carrying out the invention]

[0018] Hereinafter, embodiments for implementing the disclosures herein will be described with reference to the drawings. When subsequent embodiments have components corresponding to previously described embodiments, the same reference numerals are used and redundant descriptions are omitted. Furthermore, when only a part of the configuration is described in each embodiment, the reference numerals of the previously described embodiment may be used for other parts of that configuration. Even if it is not explicitly stated that each embodiment can be specifically combined, it is possible to partially combine embodiments as long as there is no particular impediment to such combination. In addition, the sizes of each member and component in the figures are exaggerated as appropriate for the sake of clarity in the explanation and do not represent actual dimensions or ratios between members and components.

[0019] <First Embodiment> <Structure of a siphon-type liquid transfer pump> Figure 1 is a side cross-section of a siphon-type liquid transfer pump 1 incorporating the automatic stop device 2 disclosed herein. The siphon-type liquid transfer pump 1 has a suction mechanism and a discharge mechanism via a manually operable cylinder 13. The suction mechanism has a suction valve 12 that opens and closes in accordance with the operation of the cylinder 13, such as a kerosene tank, and a suction pipe 11 that is inserted into the container that supplies the liquid, such as a stove cartridge tank. On the other hand, the discharge mechanism has a discharge valve 14 that opens and closes in accordance with the operation of the cylinder 13, and a discharge hose 15 that is inserted into the container to which the liquid is supplied. Hereinafter, in this specification, kerosene will be used as an example of the liquid to be transferred.

[0020] The intake port of the intake pipe 11 is inserted into the inlet of the kerosene tank (not shown) so that it is well below the liquid level. In the initial stage (priming process) immediately after inserting the intake pipe 11 into the kerosene tank, there is no kerosene in the operating cylinder 13, so even if the operating cylinder 13 is pushed in, only the discharge valve 14 opens, and no kerosene is discharged, resulting in a so-called dry-running state.

[0021] Subsequently, by returning the operating cylinder 13 to its original position, negative pressure is created inside the operating cylinder 13, causing the intake valve 12 to open and the kerosene in the intake pipe 11 to be drawn into the operating cylinder 13. Next, when the operating cylinder 13 is manually pushed in, its volume decreases, and the internal space of the operating cylinder 13 becomes positively pressurized. This positive pressure causes the intake valve 12 to close and the discharge valve 14 to open, and the kerosene from the operating cylinder 13 is discharged to the discharge hose 15. Furthermore, by returning the operating cylinder 13 to its original position, the volume inside the operating cylinder 13 increases, and negative pressure is created inside the operating cylinder 13. This negative pressure causes the discharge valve 14 to close and the intake valve 12 to open, and the kerosene in the intake pipe 11 is drawn into the operating cylinder 13 again. From here on, by repeating the pushing and returning operation of the operating cylinder 13, the intake and discharge cycle is established.

[0022] The automatic stop device 2 has a slide valve 211 and a float 212 positioned directly below the slide valve 211 and spaced apart from the slide valve 211. The slide valve 211 and the float 212 are housed in a storage section 213. As will be described later, the storage section 213 also has a guiding function for the levitation trajectory of the float 212.

[0023] The slide valve 211 is connected to the air inlet tube 215 via a communication hole 214 that is opened in a part of the slide track of the housing 213. One end of the air inlet tube 215 is connected to the communication hole 214, extends along the longitudinal direction of the outer surface on the discharge port side of the discharge hose 15, bends in a U shape at the discharge port, folds back along the longitudinal direction of the inner surface of the discharge hose 15, and the other end is installed inside the discharge hose 15 at a position facing the discharge valve 14 interposed between the discharge hose 15 and the operating cylinder 13 of the siphon-type liquid transfer pump 1.

[0024] The storage section 213 can have any shape as long as it can accommodate the float 212 without any excess or deficiency and has space for the sliding orbit and the levitation orbit. However, since it is attached to the outer surface of the discharge port side of the discharge hose 15, a hollow cylindrical shape is preferred. Furthermore, in order to ensure good adhesion with the outer surface shape (curvature) of the discharge port side of the discharge hose 15, it may have a deformed cylindrical shape in which the cross-section is formed in a crescent shape that follows the curvature of the outer surface shape (not shown).

[0025] The method of bonding the discharge hose 15 and the storage section 213 is not particularly limited, but in this embodiment, when the liquid being supplied is kerosene, bonding with a general adhesive may result in poor adhesion due to deterioration, swelling, etc., so a mechanical connection method using an oil-resistant hose clamp or the like is preferred.

[0026] In this embodiment, the discharge hose 15 is a bellows-shaped flexible tube with a series of ring-shaped reinforcing ribs on its outer circumference. However, the air inlet tube 215 can also be made of a material that is flexible enough to follow the bellows-like movement of the discharge hose 15 (for example, soft PVC, vinyl chloride resin, etc.). Furthermore, the cross-sectional diameter of the air inlet tube 215 is not particularly limited, as long as it is large enough to ensure sufficient space for kerosene to flow smoothly within the discharge hose 15, even when installed inside the discharge hose 15.

[0027] <Installation configuration of slide valve> The installation configuration of the slide valve 211 will be described below with reference to the top view in Figure 2 and the side view in Figure 3. In this embodiment, the slide valve 211 is formed as a plate-like body with a slit-shaped cavity 211A running through it in the longitudinal direction. When the automatic stop device 2 is not operating, the float 212 is positioned at a distance from the slide valve 211. In this state, the upper side of the slide valve 211 (the end opposite to the end facing the float 212 and the end on the opposite side where the cavity 211A is not formed) closes the communication hole 214, resulting in a closed valve state.

[0028] As the float 212 rises in response to the rise in the kerosene liquid level, the slide valve 211 located above the float operates (is pushed up) in accordance with the float 212's rise, causing a portion of the upper part of the cavity 211A to overlap with the communication hole 214 and open.

[0029] When the valve is opened, the space inside the storage section 213 and the air inlet tube 215 are connected via the communication hole 214, allowing air to be supplied to the air inlet tube 215.

[0030] The communication hole 214 opens into the support portion 216 of the slide valve 211, which is formed in the housing portion 213. The slide valve 211 is slidably mounted through a guide hole 216A, which penetrates from the upper surface of the housing portion 213 on the support portion 216 side, passing through the communication hole 214. Therefore, the guide hole 216A has the function of guiding the sliding trajectory of the slide valve 211. In addition, the communication hole 214 connects the guide hole 216A to the outside of the housing portion 213 in the support portion 216.

[0031] Therefore, when the slide valve 211 operates in response to the rise of the float 212, it slides through the guide hole 216A of the support portion 216 so as to protrude directly upward from the upper surface. However, sliding movement is not an absolute requirement for the guide hole 216A, as long as it maintains its guiding function that enables movement in the directly upward direction, and the width dimension of the guide hole 216A may be such that the slide valve 211 is loosely fitted.

[0032] In Figure 3, the communication hole 214 is located in the support portion 216, opening towards the air inlet tube 215 side than the guide hole 216A. However, as shown in Figure 4, the support portion 216 may be formed as a through-hole 217 that penetrates horizontally in the short direction of the storage portion 213 and reaches the air inlet tube 215 side. The through-hole 217 is easy to manufacture and can take in more air.

[0033] <Float installation configuration> The float installation configuration will be explained using Figure 5. As described above, the float 212 is made of a material that floats to detect the liquid level as the kerosene level rises. Therefore, it can be any oil-resistant material that has a lower specific gravity than kerosene and does not deteriorate or deform when immersed in kerosene. For example, nitrile butadiene rubber (NBR), fluororesin, and phenolic resin are preferred. The shape can be any shape that allows it to float and lift the slide valve 211 (for example, a rectangular shape, a sphere, etc.).

[0034] In Figures 1 to 4, the float 212 is shown in a configuration separated from the slide valve 211 (when the valve is closed), but it may also be fixedly connected to the slide valve 211 (not shown).

[0035] Furthermore, as shown in Figure 5, the connection may also be made via a linear member 218 connected to the connection portion 211B at the lower end of the float 212 side of the slide valve 211. The linear member 218 may be a rod-shaped rigid member, but a thread-like flexible member is preferred. The thread-like flexible member may be a general thread made from animal or plant fibers or artificial fibers, but if the target of the liquid being transported is kerosene, a material that has oil resistance and can maintain mechanical strength for a long period of time is more preferable, i.e., a fluorocarbon fiber or a metal wire such as stainless steel.

[0036] The linear member 218, made of the flexible material, avoids the rigid, immediate transmission of buoyancy and prevents chattering (small on / off cycles) of the slide valve 211. It also prevents malfunctions caused by the direct transmission of effects such as water surface ripple, vibration, and tilt to the slide valve 211, and ensures stable operation. Furthermore, the float 212 is always aligned vertically with the slide valve 211 by its own weight, preventing misalignment and angular misalignment between the slide valve 211 and the float 212.

[0037] Furthermore, the bottom surface of the lower end of the storage section 213 on the float 212 side is open, allowing kerosene to enter and thereby causing the float 212 to float. As described above, the slide valve 211 and the float 212 can be arranged in various ways, such as spaced apart, fixedly connected, or connected via a linear member 218, but in any case, the float 212 should be fitted so as to be supported in contact with the inner wall surface of the storage section 213 so as not to fall out of the opening (not shown). However, the width of the float 212 must be set at a level where the friction of the contact surface between the float 212 and the storage section 213 does not hinder the floating force.

[0038] In this embodiment (Figure 5), in order to more easily prevent the above-mentioned detachment, a mesh seating portion 219 that allows kerosene to enter is provided at the opening of the storage portion 213.

[0039] Alternatively, the seating portion 219 may be provided with a rib-shaped stopper that protrudes in the inner circumferential direction of the opening, and a flange may be formed on the outer circumference of the lower end surface of the float 212, with the flange resting on the stopper (not shown).

[0040] <Lock mechanism for air inlet tube> Figure 6 is a schematic diagram showing a partially enlarged view of the latching structure of the air inlet tube 215. The air inlet tube 215 is installed inside the discharge hose 15 so that its outlet faces the discharge valve 14. However, as mentioned above, the air inlet tube 215 is made of a flexible material, so the outlet may bend downwards, which could prevent the air blown out from the outlet from efficiently hitting the discharge valve 14. Therefore, an L-shaped hook 220 is provided protruding from the end of the air inlet tube 215 on the discharge valve 14 side, a concave latching hole 17 is formed on the upper inner wall surface of the discharge hose 15 on the discharge valve 14 side, and the hook 220 can be latched into the latching hole 17.

[0041] <Operation process of the automatic stop device> The operation process of the automatic stop device 2 will be explained using Figures 7 and 8.

[0042] First, the operation process of the slide valve 211 in the closed state will be explained with reference to Figure 7. The pumping operation (reciprocating motion) of the operating cylinder 13 draws up kerosene from the poly container (not shown) through the suction pipe 11 by opening the suction valve 12. That is, after the priming process, the suction process of the operating cylinder 13 closes the discharge valve 14 and opens the suction valve 12, drawing up kerosene from the suction pipe 11 and sending it to the operating cylinder 13. Subsequently, the extrusion process of the operating cylinder 13 closes the suction valve 12 and opens the discharge valve 14, sending kerosene to the discharge hose 15, and supplying kerosene L to the destination container, i.e., tank T, such as a cartridge-type kerosene tank. If there is a water level difference after the initial pumping, refueling will continue even without the reciprocating motion of the operating cylinder 13 due to the siphon effect.

[0043] From this point onward, the supply of kerosene L to tank T continues by the reciprocating motion of the operating cylinder 13 (or by siphon action) until the liquid level S of the kerosene L in tank T reaches the float 212 of the automatic stop device 2.

[0044] At this time, the slide valve 211 is closed in the state before the float 212 rises, with the communication hole 214 blocked in the portion of the slide valve 211 where the cavity 211A has not yet been formed. In Figure 7, the flow of kerosene L in the discharge hose 15 is indicated by the black arrow.

[0045] Figure 8 illustrates the operation process of the slide valve 211 in the closed state. When kerosene L is continuously supplied to the tank T and the liquid level S rises, it reaches the float 212 of the automatic stop device 2, causing the float 212 to rise. In response to the rise of the float 212, the slide valve 211 is also guided by the guide hole 216A and moves so as to protrude directly upward from the upper surface of the housing 213. When the slide valve 211 moves and the cavity 211A overlaps the communication hole 214, the slide valve 211 opens, and the air held on the upper side of the housing 213 is sent out from the other end of the air inlet tube 215 to close the discharge valve 14, thereby restricting the liquid flow in the discharge hose 15 and stopping the liquid supply from the siphon-type liquid transfer pump 1. Even when refueling is performed by the siphon action, closing the discharge valve 14 interrupts the continuous liquid column and releases the siphon action. In Figure 8, the airflow within the air inlet tube 215 is indicated by white arrows.

[0046] As described above, the automatic stop device 2 disclosed herein can effectively control the airflow through the operation process of a slide valve 211 with a simple structure, and can reliably and quickly close the discharge valve 14.

[0047] <Second Embodiment> Figure 9 shows a siphon-type liquid transfer pump 1 according to the second embodiment. In the siphon-type liquid transfer pump 1 according to the first embodiment, the air inlet tube 215 is housed inside the discharge hose 15, but in the siphon-type liquid transfer pump 1 according to this embodiment, the external air inlet tube 221 is housed outside the discharge hose 15, running parallel to it.

[0048] The air outlet end (the other end) of the externally enclosed air inlet tube 221 is airtightly inserted into the internal space from the discharge hose 15 just before the discharge valve 14.

[0049] The external air inlet tube 221 can be secured with multiple mounting members 222 so that it runs parallel to the discharge hose 15. The mounting members 222 can be mechanical fastening members such as strings, adhesive tapes, or cable ties.

[0050] According to this embodiment, the external air inlet tube 221 can maintain the flow path space of the discharge hose 15 as it was before the automatic stop device 2 was installed. In addition, it becomes easier to retrofit the automatic stop device 2 to an existing siphon-type liquid transfer pump 1.

[0051] <Third Embodiment> Figure 10 shows a siphon-type liquid transfer pump 1 according to the third embodiment. In the siphon-type liquid transfer pump 1 according to the first and second embodiments, the end of the external air inlet tube 221 on the discharge valve 14 side (the other end) is positioned opposite the discharge valve 14 on the discharge hose 15 side. However, in this embodiment, the extended air inlet tube 223 is an extension of the slide valve 211 enclosed in the automatic stop device 2. That is, it extends from the internal space of the discharge hose 15, airtightly passing through the partition wall where the discharge valve 14 is located, avoiding the discharge valve 14, and extending into the internal space of the operating cylinder 13.

[0052] In this configuration, the air released by opening the slide valve 211 is supplied directly to the internal space of the working cylinder 13. When air is supplied to the internal space of the working cylinder 13, the intake valve 12 closes, stopping the refueling, and the discharge valve 14 opens, allowing the kerosene remaining inside the working cylinder 13 and discharge hose 15 to be discharged. In a siphon-type liquid transfer pump 1 that does not have an automatic stop device 2, the same effect can be achieved by opening the air vent 16, but normally the air vent 16 is screwed in by a screw cap, which requires a complicated process (effort) of turning, and does not allow for the rapid discharge of residual liquid.

[0053] According to this embodiment, the supply of kerosene can be stopped and any remaining liquid can be quickly discharged by operating the slide valve 211 (i.e., by an automatic and single process of opening the slide valve 211).

[0054] The technology disclosed in this specification is not limited to the embodiments described above. That is, it encompasses the exemplary embodiments and variations thereof by those skilled in the art. It also encompasses the substitution or combination of parts, elements between one embodiment and another. Furthermore, the scope of the disclosed technology is not limited to the descriptions of the embodiments. The scope of the disclosed technology is indicated by the claims and further includes all modifications within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0055] 1. Siphon-type liquid transfer pump 2 Automatic stop device 11 Suction pipe 12 Intake valve 13 Actuator cylinder 14 Discharge valve 15 Discharge hose 16 Air vents 17 Latch hole 211 Slide valve 212 Floats 213 Storage compartment 214 Communication hole 215 Air Inlet Tube 216 Support part 217 Through-hole 218 Linear member 219 Seating area 220 hooks 221 External air inlet tube 222 Mounting components 223 Extendable air inlet tube 211A Cavity 211B Connection 216A Guide hole

Claims

1. A float is positioned on the discharge port side of the discharge hose of a siphon-type liquid transfer pump, and in the container to which the liquid is being transferred, it rises as the liquid level increases, thereby detecting the liquid level. A storage section that houses the float, has an opening at the bottom that allows the liquid to enter as the liquid level rises, holds air above the float, and guides the float in the direction of buoyancy, Inside the aforementioned storage compartment, a slide valve is positioned above the float in the direction of its upward movement and operates in accordance with the float's upward movement. The cavity formed in the slide valve, The aforementioned storage section includes a support portion for the slide valve having a guide hole for guiding the operation of the slide valve, The support portion has a communication hole that connects the guide hole and the outside of the storage portion, It has an air inlet tube, one end of which is connected to the communication hole, and the other end of which is installed inside the discharge hose at a position facing the discharge valve interposed between the discharge hose and the operating cylinder of the siphon-type liquid transfer pump, An automatic stop device that closes the communication hole and shuts the valve in the portion of the slide valve where the cavity is not formed in the state before the float rises, the slide valve is fitted through a guide hole that penetrates from the upper surface on the support side of the housing portion through the communication hole, operates along the guide hole in response to the float rising, moves so as to protrude directly upward from the upper surface, opens the valve when the cavity overlaps the communication hole, and shuts the discharge valve by sending air held on the upper side of the housing portion from the other end of the air inlet tube, thereby restricting the liquid flow in the discharge hose and stopping the liquid supply of the siphon type liquid transfer pump.

2. The automatic stop device according to claim 1, wherein the slide valve is formed of a plate-like body, and the cavity is formed by slitting through the plate-like body in the longitudinal direction.

3. The automatic stop device according to claim 1, wherein the communication hole is formed as a through-hole that penetrates the support portion transversely in the short direction of the storage portion and goes through to the air inlet tube.

4. The automatic stop device according to claim 1, wherein the storage compartment has a seating portion for the float on its bottom surface that allows the liquid to enter.

5. The automatic stop device according to claim 1, wherein the float is positioned spaced apart directly below the slide valve, or is fixedly connected directly below the slide valve.

6. The automatic stop device according to claim 1, wherein the float is connected to the slide valve via a linear member.

7. The automatic stop device according to claim 1, wherein the air inlet tube has an L-shaped hook protruding from the other end, and the hook is hooked into a concave locking hole formed on the inner wall surface of the discharge hose.

8. The automatic stop device according to claim 1, wherein the air inlet tube is inserted into the internal space of the discharge hose.

9. The automatic stop device according to claim 1, wherein the air intake tube is mounted parallel to the discharge hose and its other end is airtightly inserted into the internal space from the discharge hose before the discharge valve.

10. The automatic stop device according to claim 1, wherein the air inlet tube extends from the internal space of the discharge hose, airtightly through the partition wall portion where the discharge valve of the siphon-type liquid transfer pump is provided, avoiding the discharge valve, and into the internal space of the operating cylinder.

11. A siphon-type liquid transfer pump having an automatic stop device according to any one of claims 1 to 10.

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