JP6364284B2 - Liquid discharge pump - Google Patents

Description

  The present invention relates to a pump that discharges various liquids in a container in appropriate amounts, and more particularly to a so-called back suction type pump that prevents dripping.

  Conventional pumps of this type are used for cosmetics and shampoo containers, and are known in various configurations. For example, a piston that can reciprocate in a cylinder is provided with a passage that leads to a discharge port and a lateral hole that communicates with the passage, and when the piston is pushed in, a first position that communicates the passage and the inside of the cylinder via the lateral hole. At the time of return of the piston, a seal valve that is in a second position that cuts off the communication is attached to the piston, while the seal valve moves from the first position to the second position, and the piston, the seal valve, There is a type in which a communication passage that communicates the space formed between the passage and the passage is provided, and a check valve is disposed in the cylinder (Patent Document 1).

  In this conventional example, when the piston is pushed in, the liquid in the cylinder is discharged from the discharge port, and when the piston returns, the seal valve moves from the first position to the second position to close the lateral hole. In addition, the discharge of the liquid from the discharge port is stopped, and then, by further raising the piston, a space is formed between the seal valve and the passage leading to the discharge port is made negative pressure, Part of the remaining liquid is drawn into the space through the communication path. As a result, the residual liquid near the discharge port is sucked into the back to prevent dripping, while the piston is further lifted, so that the pressure in the cylinder is reduced, the check valve is opened, and the liquid in the container is discharged. It sucks into the cylinder.

Japanese Utility Model Publication No.3-115066

  According to the conventional configuration, the seal valve moves from the first position to the second position, a space is formed between the seal valve and the piston, and the inside of the passage leading to the discharge port is negatively pressured. When a part of the liquid remaining in the passage is drawn into the space through the space, the space is small and a sufficient suction force cannot be obtained, and the amount of liquid drawn into the space is small. There is also a disadvantage that the amount of the residual liquid sucked into the back is small, and a sufficient dripping prevention effect cannot be achieved. And since the horizontal hole is closed at the time of the suction | attraction of this liquid, this horizontal hole has nothing to do with the suction action. Further, at the time of sucking the liquid, the check valve is not involved in the suction action because the passage leading to the discharge port and the cylinder are not in communication. An object of the present invention is to provide a liquid discharge pump capable of solving the above-described disadvantages and exhibiting sufficient dripping prevention action.

In order to achieve this object, a liquid discharge pump according to a first aspect of the present invention includes a cylinder provided at an upper portion of a container main body that stores liquid and having an opening for communicating with the container, and the opening of the cylinder. A check valve that opens and closes, a piston that communicates the inside of the cylinder with the liquid discharge port and that can be reciprocated up and down with respect to the cylinder, and moves up and down along with the piston. The piston has a first and a second communication hole for communicating with the inside of the cylinder with a space in the vertical direction, and the inside of the cylinder. When the seal valve is in the uppermost position together with the piston, the piston and the cylinder are not communicated with each other. When the piston descends against the elastic force, the piston and the cylinder are brought into communication with each other, and when the piston reaches a predetermined position, the piston moves down with the piston and maintains the communication state. When the piston rises from the lowest position by elasticity, the piston rises together with the piston.When the piston reaches a predetermined position, the piston and the cylinder are disconnected, and the piston and the piston are in the uppermost position. The check valve is elastically energized in the closing direction by a spring having a weaker elastic force than the spring arranged between the spring and the cylindrical stopper that is elastically supported by the cylinder by the spring. It is configured as described above.

  While the piston rises from the lowest position, the volume in the cylinder increases while the inside of the piston is in communication with the inside of the cylinder. Then, the liquid in the piston is sucked into the cylinder from each communication hole, and accordingly, the liquid remaining on the liquid discharge port side of the pump is sucked into the piston to prevent dripping. At this time, the check valve is prevented from being inadvertently actuated by a spring disposed between the check and the cylindrical stopper, and maintains a stable closed state.

According to the liquid discharge pump according to claim 1 of the present invention, the liquid remaining on the liquid discharge port side of the pump is sucked into the cylinder through the first and second communication holes provided in the piston. Since a large amount of liquid can be instantaneously aspirated, the suction operation is reliable, and it is possible to reliably prevent dripping, and when the liquid remaining on the liquid discharge port side of the pump is sucked into the cylinder, Since the check valve maintains a stable closed state, the suction operation becomes more reliable, and there is an effect that dripping can be reliably prevented .

The center longitudinal cross-sectional view which shows the time of the standby state which has a piston in the highest position in one suitable embodiment of this invention. The center longitudinal cross-sectional view which shows the time of the discharge operation | movement of the liquid by the fall of a piston similarly. The center longitudinal cross-sectional view which shows the time of completion | finish of discharge which similarly has a piston in the lowest position. Similarly, the center longitudinal cross-sectional view which shows the time of the suction operation of the liquid by the raise of a piston.

  Hereinafter, a preferred embodiment of the present invention will be described. As shown in FIGS. 1 to 4, a male screw is engraved on the outer peripheral surface of the upper small-diameter portion 1a of a synthetic resin-made bottomed cylindrical container body 1 (only part of which is shown), and the upper small-diameter portion 1a. Further, a pump mounting cylinder 2 having an internal thread engraved on the inner peripheral surface is screwed. A pump 3 for discharging an appropriate amount of liquid filled in the container body 1 to the outside of the container body 1 is fixedly attached to the pump mounting cylinder 2. A fitting cylinder 5 a of the drive head 5 is fitted to the substantially cylindrical upper piston 4 located at the upper end of the pump 3. The lower end of the outer peripheral surface of the drive head 5 is positioned corresponding to the inside of an annular projecting wall 2 a that is integrally provided upright on the upper surface of the pump mounting cylinder 2. Further, the drive head 5 is provided with a liquid discharge port 5b so as to communicate with the inside of the upper piston 4 through the fitting cylinder 5a.

  Here, the configuration of the pump 3 will be described. The upper piston 4 is supported by the guide hole 2b of the pump mounting cylinder 2 so as to be movable up and down, and the lower part is a large diameter part 4a to form a stepped part 4b. The outer diameter of the large diameter part 4a is the pump mounting cylinder. It is formed so as to be slidable on the inner peripheral surface of the second guide wall 2c. An upper end portion of the lower piston 6 is fitted and fixed to the upper piston 4. The lower piston 6 has a cylindrical shape at the top and a round bar at the bottom, and a skirt portion 6a is formed at the boundary between them, and a pair of upper and lower communication holes 6b and 6c are provided at the upper portion. An engagement step 6d is provided at the lower end of the skirt 6a.

  The substantially cylindrical cylinder 7 in which the pistons 4 and 6 reciprocate up and down in the inside thereof has an annular projecting wall 7a at the upper end thereof fitted in the fitting groove 2d of the pump mounting cylinder 2, and an annular flange 7b is provided in the packing. 8 is fixed by being sandwiched from above and below by the pump mounting cylinder 2 and the container body 1. An opening 9 is provided at the lower end of the cylinder 7, a valve seat 15 is provided on the inner surface adjacent to the opening 9, and a ball valve 10 that is a check valve is disposed on the valve seat 15. In the vicinity of the valve seat 15, a cylindrical stopper 11 having a locking portion 11a which is annular and has a lower end portion whose diameter is enlarged like a bowl is disposed. The inner diameter of the cylindrical stopper 11 is large enough for the round bar portion of the lower piston 6 to enter.

A spring 12 is arranged between the engaging portion 11a of the cylindrical stopper 11 and the engaging step portion 6d of the lower piston 6, and elastically biases the lower piston 6 upward, while the cylindrical stopper 11 Is energized downward. Further, a spring 13 is disposed between the stepped portion 11b formed on the inner peripheral surface of the cylindrical stopper 11 and the ball valve 10 to elastically urge the ball valve 10 downward, and the cylindrical stopper 11 Is energized upward. The spring force of the spring 13 is set to be weaker than the spring force of the spring 12, and the cylindrical stopper 11 cannot be moved upward, while the pressure in the cylinder 7 is the pressure in the container body 1. The ball valve 10 is set in close contact with the valve seat 15 so that the closed state can be maintained until it becomes smaller than a predetermined value.

  Between the upper outer peripheral surface of the lower piston 6 and the inner peripheral surface of the cylinder 7, a double annular seal valve 14 connected at the lower portion is slidably disposed. The seal valve 14 has a large number of protruding edges formed at intervals around the entire inner peripheral surface of the inner ring 14a, and applies an appropriate frictional force to the outer peripheral surface between the pair of communication holes 6b, 6c of the lower piston 6. The outer ring 14b is in sliding contact with the inner peripheral surface of the cylinder 7 with an appropriate frictional force at the outer peripheral surfaces of the upper and lower ends of the outer ring 14b. A large number of concave grooves exist over the entire circumference between the protruding edges, which are the sliding contact surfaces of the seal valve 14 with the lower piston 6, and the upper and lower spaces communicate with each other through these concave grooves.

  In the standby state in which the pistons 4 and 6 shown in FIG. 1 are in the uppermost position, the seal valve 14 is in close contact with the skirt 6a of the lower piston 6 at the lower end of the inner ring 14a and the upper end of the outer ring 14b at the pump mounting cylinder 2. The space in the cylinder 7 and the space in the upper and lower pistons 4 and 6 are shut off in close contact with the lower end of the protruding wall 2c. On the other hand, at the end of discharge when the pistons 4 and 6 in FIG. 3 are at the lowest position, the lower end of the outer ring 14b is in close contact with the step 7c of the cylinder 7 and the upper end of the inner ring 14a is the upper piston 4 The space in the cylinder 7 and the space in the upper and lower pistons 4 and 6 are in communication with each other in close contact with the step 4b.

  Then, operation | movement of the pump 3 comprised as mentioned above is demonstrated. In a standby state in which the container body 1 is filled with liquid (not shown) (see FIG. 1), when the drive head 5 is pushed down, the upper and lower pistons 4 and 6 are also lowered against the elastic force of the spring 12. The skirt portion 6a of the lower piston 6 is separated from the lower end of the inner ring 14a of the seal valve 14 so that the space in the cylinder 7 and the space in the lower piston 6 that are in the cut-off state are connected to the communication hole 6b, the concave groove, and the communication hole. The communication state is established via 6c. As a result, the pressure in the space below the skirt portion 6a in the cylinder 7 is increased, and this pressure allows the liquid in the space below the skirt portion 6a to pass through the communication hole 6c and to communicate with the concave groove of the seal valve 14. It starts to move into the lower piston 6 through the hole 6b.

  As the drive head 5 is lowered, the step 4b of the upper piston 4 and the upper end of the inner ring 14a of the seal valve 14 are brought into close contact with each other, and the seal valve 14 is lowered together with the upper and lower pistons 4 and 6, When the pressure in the space below the portion 6a further increases, the liquid in the upper and lower pistons 4 and 6 begins to be discharged from the liquid discharge port 5b (see FIG. 2). When the drive head 5 is further pushed down and the lower end of the outer ring 14b of the seal valve 14 is brought into close contact with the step 7c of the cylinder 7, the lowering is prevented and the lower piston 6 reaches the lowest position (see FIG. 3). In this state, the pressure on the liquid in the piston 7 becomes maximum, and the liquid discharge operation from the liquid discharge port 5b is completed. The liquid remains in the liquid discharge port 5b, and depending on the viscosity of the liquid, the liquid discharge port 5b protrudes from the liquid discharge port 5b due to surface tension.

  Here, when the push-down force applied to the drive head 5 is released, the upper and lower pistons 4 and 6 are moved upward by the elastic force of the spring 12, so that the volume in the cylinder 7 increases and the outside of the container is increased. The liquid in the upper and lower pistons 4, 6 is drawn into the cylinder 7 through the communication hole 6 b and the concave groove and the communication hole 6 c, and the liquid remaining in the liquid discharge port 5 a together with the piston 4. , 6 (see FIG. 4). This prevents dripping.

At this time, the ball valve 10 is kept in close contact with the valve seat 15 by the elastic force of the spring 13, so that the liquid in the container body 1 flows into the cylinder 7 even when the pressure in the cylinder 7 decreases. The suction operation in which the negative pressure state in the cylinder 7 is maintained and the liquid in the upper and lower pistons 4 and 6 is drawn into the cylinder 7 through the communication hole 6b, the concave groove and the communication hole 6c. In addition, the suction operation for drawing the liquid remaining in the liquid discharge port 5a into the pistons 4 and 6 is performed reliably. In addition, since the liquid is drawn from the pair of upper and lower communication holes 6b and 6c, this suction operation is performed more quickly than in the case of one communication hole.

  When the upper and lower pistons 4 and 6 are raised and the lower end of the inner ring 14a of the seal valve 14 is brought into contact with the skirt portion 6a, the cylinder 7 and the upper and lower pistons 4 and 6 are cut off. The suction operation is stopped, and the seal valve 14 rises together with the upper and lower pistons 4 and 6. When the upper and lower pistons 4 and 6 are further raised, the pressure in the cylinder 7 becomes smaller, and when the pressure is lower than the predetermined pressure, the ball valve 10 is opened against the elastic force of the spring 13, and the cylinder The liquid in the container body 1 flows into 7. When the pressure in the cylinder 7 exceeds a certain level due to this inflow, the ball valve 10 returns to the closed state again by the elastic force of the spring 13, and the cylinder 7 and the container body 1 are brought into a non-communication state.

  When the upper and lower pistons 4 and 6 are further raised and the upper end of the outer ring 14b of the seal valve 14 comes into contact with the lower end of the guide wall 2c of the pump mounting cylinder 2, the drive head 5, the upper and lower cylinders 4 and 6 and the seal valve The ascending motion 14 stops and enters a standby state (see FIG. 1) for the next motion.

The present invention is not limited to the implementation described above, for example, upper piston 4 and the lower piston 6 may be formed integrally rather than separately. Moreover, each communicating hole 6b, 6c is not limited to a pair, respectively, For example, you may provide three each.

DESCRIPTION OF SYMBOLS 1 Container body 2 Pump mounting cylinder 2a Projection wall 2b Guide hole 2c Guide wall 2d Fitting groove 3 Pump 4 Upper piston 4a Large diameter part 4b Step part 5 Drive head 5a Fitting cylinder 5b Liquid discharge port 6 Lower piston 6a Skirt part 6b 6c Communicating hole 6d Engaging step portion 7 Cylinder 7a Annular protruding wall 7b Annular flange 7c Step portion 8 Packing 9 Opening 10 Ball valve 11 Cylindrical stopper 11a Locking portion 11b Step portion 12, 13 Spring 14 Seal valve 15 Valve seat

Claims (1)

A cylinder provided at the upper part of the container main body for containing the liquid and having an opening for communicating with the container main body, a check valve for opening and closing the opening of the cylinder, the cylinder and the liquid discharge port communicating with each other, and the cylinder A piston provided so as to be capable of reciprocating up and down, and a seal valve that moves up and down along with the piston to bring the piston and the cylinder into communication or non-communication,
The piston has first and second communication holes for communicating with the cylinder at an interval in the vertical direction, and is elastically biased upward by a spring disposed in the cylinder.
When the seal valve is in the uppermost position together with the piston, the inside of the piston and the inside of the cylinder are brought into a non-communication state, and when the piston descends against an elastic force, the non-communication state is brought into a communication state, When the piston reaches a predetermined position, it descends together with the piston to reach the lowest position, and when the piston rises from the lowest position by an elastic force, it rises together with the piston and moves to the predetermined position. When it reaches, the inside of the piston and the inside of the cylinder are in a non-communication state, and the piston is returned to the uppermost position together with the piston ,
The check valve is configured to be elastically biased in the closing direction by a spring having a weaker elastic force than the spring arranged between the spring and the cylindrical stopper that is elastically supported by the cylinder. A liquid discharge pump.

Images