JP3715351B2 - Reciprocating pump - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a reciprocating pump that compresses and discharges fluid sucked into a cylinder by reciprocating a piston in the cylinder.
[0002]
[Prior art]
First, a reciprocating pump will be described by taking a piston pump as an example. FIG. 3 is a front sectional view showing a conventional piston pump.
[0003]
In the figure, a piston pump 1 reciprocates a piston 3 in a cylinder 2 to suck air into the cylinder 2 from a suction chamber 4 communicating with the atmosphere through a suction hole 6 opened and closed by a suction valve 5. A configuration in which compressed air in the cylinder 2 is discharged into a discharge chamber 9 through a discharge hole 8 that is opened and closed by a discharge valve 7, and compressed air is supplied to an air tank or the like through a discharge pipe (not shown). It has become.
[0004]
[Problems to be solved by the invention]
However, according to the above-described piston pump 1, when the piston pump 1 is stopped, the compressed air remains in the cylinder 2, the discharge chamber 9, and the discharge pipe (not shown). Therefore, when the piston pump 1 is restarted, the compressed air in the cylinder 2 prevents the piston 3 from reciprocating, and the residual air in the discharge chamber 9 and the discharge pipe prevents the discharge valve 8 from opening. As a result, the driving force of a motor that is a driving source for reciprocating the piston 3 is insufficient, and the piston pump 1 may not be restarted. In such a case, an excessive load is applied to the motor, which may damage the motor.
[0005]
Therefore, as a means for solving such a problem, for example, a technique described in Japanese Utility Model Publication No. 5-7513 has been proposed. According to this technique, an orifice path is provided in a cylinder head or a suction valve so that compressed air remaining in the cylinder is released to the atmosphere.
[0006]
However, the above technique causes the following new problem. That is, the orifice path provided in the cylinder head or the suction valve is formed with a minute diameter that does not hinder the pump function. For this reason, when foreign matter such as dust is sucked into the suction chamber while the piston pump is being driven, the foreign matter may be clogged in the orifice path and the orifice path may be blocked. If the orifice path is blocked, compressed air remains in the cylinder and cannot perform its function sufficiently.
[0007]
An object of this invention is to provide the reciprocating pump which can perform a restart easily.
[0008]
[Means for Solving the Problems]
The present invention includes a cylinder, a piston that is reciprocally movable in the cylinder, a cylinder head that is provided at a top dead center side end portion of the piston in the cylinder, and includes a suction chamber and a discharge chamber. A suction hole provided in a cylinder head for communicating the cylinder and the suction chamber; a suction valve provided in an opening of the suction hole on the cylinder side; and opening and closing the suction hole; and a cylinder provided in the cylinder head. In the reciprocating pump having a discharge hole that communicates with the discharge chamber, and a discharge valve that opens and closes the discharge hole and is provided at an opening of the discharge hole on the discharge chamber side, the suction hole is formed in the cylinder head. A recess is formed adjacent to the cylinder side opening in the cylinder, and a communication groove is formed to connect the recess to the suction hole. Characterized in that communicated.
[0009]
[Action]
According to the present invention, a concave portion is formed in the cylinder head adjacent to the cylinder side opening in the suction hole, and a communication groove that communicates the concave portion and the suction hole is formed. Since the communication is made, the residual pressure in the cylinder can be discharged to the outside of the cylinder through the communication groove.
[0010]
【Example】
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front sectional view showing a configuration of a piston pump according to the present invention, and FIG. 2 is an enlarged view showing the vicinity of a suction hole.
[0011]
The piston pump 10 includes a cylinder 11, a piston 12 that is reciprocally movable in the cylinder 11, and a suction chamber 13 and a discharge chamber 14 that are provided at the top dead center side end of the piston 12 in the cylinder 11. The cylinder head 15, the suction hole 16 provided in the cylinder head 15 for communicating the cylinder 11 and the suction chamber 13, and the opening 16 a on the cylinder 11 side of the suction hole 16 are opened and closed. A discharge valve 18 that communicates with the discharge chamber 14, and a discharge valve 19 that is located in the opening 18 a of the discharge hole 18 on the discharge chamber 14 side and opens and closes the discharge hole 18.
[0012]
The piston 12 is integrally provided with a connecting rod 20, and the end of the connecting rod 20 is rotatably connected to an eccentric shaft of a balance weight 22 fixed to a rotating shaft 21 of a motor (not shown). ing.
[0013]
The suction chamber 13 is communicated with the atmosphere via a suction pipe (not shown), and the discharge chamber 14 is connected to an air tank (not shown) or the like via a discharge pipe 23.
[0014]
Since the shape of the suction valve 17 and the discharge valve 19 is substantially the same, only the suction valve 17 will be described with reference to FIG. The suction valve 17 is formed of a leaf spring and includes a fixed portion 17a and a valve portion 17b. The suction valve 17 is fixed to the cylinder head 15 with a fixing portion 17 a by a screw 24. Further, the valve portion 17b is formed in a circular shape having a diameter larger than the diameter of the suction hole 16, and faces the suction hole 16 and closes the suction hole 16 when the piston pump 10 is stopped.
[0015]
As shown in FIG. 2, the cylinder head 15 is formed with a recess 25 having a predetermined depth at a position adjacent to the opening 16 a of the suction hole 16 and not blocked by the suction valve 17. Further, a communication groove 26 that communicates the recess 25 and the suction hole 16 is formed. The communication groove 26 always communicates with the inside of the cylinder 11 and the suction hole 16 even when the opening 16 a of the suction hole 16 is closed by the suction valve 17.
[0016]
Next, the operation will be described.
[0017]
The piston pump 10 is driven and stopped by turning a power switch (not shown) “ON” and “OFF”. That is, when the power switch is turned “ON”, the motor is driven and the piston 12 starts to reciprocate within the cylinder 11. During the forward movement of the piston 12 (suction process), the pressure inside the cylinder 11 becomes negative. As a result, the suction valve 17 is opened and air is sucked into the cylinder 11 from the suction chamber 13 through the suction hole 16. Is done. When the piston 12 moves backward (discharge process), the atmosphere in the cylinder 11 is compressed. As a result, the discharge valve 19 is opened, and the compressed air in the cylinder 11 enters the discharge chamber 14 through the discharge hole 18. Discharged. The compressed air discharged into the discharge chamber 14 is supplied to the air tank via the discharge pipe 23. The piston pump 10 in the driving state is stopped by turning off the power switch.
[0018]
When the piston pump 10 is thus stopped, compressed air remains in the cylinder 11, the discharge chamber 14, and the discharge pipe 23. However, the compressed air in the cylinder 11 flows out into the suction chamber 13 through the recess 25, the communication groove 26, and the suction hole 16, and is released to the atmosphere through a suction pipe (not shown). For this reason, after the piston pump 10 stops, the pressure in the cylinder 11 is returned to a low pressure.
[0019]
According to the above embodiment, the recess 25 having a predetermined depth is formed in the cylinder head 15 at a position adjacent to the opening 16a of the suction hole 16, and the communication groove 26 that connects the recess 25 and the suction hole 16 is formed. Therefore, when the piston pump 10 is stopped, the compressed air remaining in the cylinder 11 flows into the suction chamber 13 through the recess 25, the communication groove 26, and the suction hole 16, and passes through a suction pipe (not shown). Released into the atmosphere. For this reason, when the piston pump 10 is stopped, the pressure in the cylinder 11 can be reduced. Therefore, when the piston pump 10 is restarted, the motor is not subjected to an excessive load and can be restarted easily.
[0020]
Further, according to the above embodiment, by providing the recess 25 and the communication groove 26, the communication groove 26 is covered with the suction valve 17 to form an orifice-shaped passage when the piston pump 10 is stopped. The communication groove 26 that constantly communicates the inside of the cylinder 11 and the suction chamber 13 has a groove shape because the suction valve 17 releases the suction hole 16 during the suction process while the piston pump 10 is being driven. Therefore, even if foreign matter such as dust is sucked into the suction chamber 13 while the piston pump 10 is being driven, the phenomenon that the foreign matter is clogged in the communication groove 26 and the communication groove 26 is blocked can be prevented. Therefore, when the piston pump 10 is stopped, the compressed air in the cylinder 11 can be always released in a good state.
[0021]
【The invention's effect】
According to the present invention, the reciprocating pump can be easily restarted.
[Brief description of the drawings]
FIG. 1 is a front sectional view showing a configuration of a piston pump according to the present invention.
FIG. 2 is an enlarged view showing the periphery of a suction hole.
FIG. 3 is a front sectional view showing a conventional piston pump.
[Explanation of symbols]
10 piston pump 11 cylinder 12 piston 13 suction chamber 14 discharge chamber 15 cylinder head 16 suction hole 16a opening 17 suction valve 18 discharge hole 18a opening 19 discharge valve 25 recess 26 communication groove

Claims (1)

A cylinder, a piston that is reciprocally movable in the cylinder, a cylinder head that is provided at a top dead center side end of the piston in the cylinder, and in which a suction chamber and a discharge chamber are formed; and provided in the cylinder head A suction hole communicating with the cylinder and the suction chamber; a suction valve provided at an opening of the suction hole on the cylinder side; for opening and closing the suction hole; and a cylinder provided at the cylinder head and the discharge chamber. In a reciprocating pump having a discharge hole that communicates with the discharge hole and a discharge valve that is provided at an opening of the discharge hole on the discharge chamber side to open and close the discharge hole, the cylinder head has a cylinder-side opening in the suction hole. A recess is formed adjacent to the portion, and a communication groove is formed to connect the recess to the suction hole, so that the cylinder and the suction chamber are always in communication. Reciprocating pump, characterized in that.

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