JPH0722087U - Reciprocating pump - Google Patents

Abstract

(57) [Summary] [Purpose] When the intake / exhaust cycle of the plunger pump 10 is used for intermittent injection of water 92, the pressure of the water 92 intermittently discharged from the plunger pump 10 is increased. [Constitution] The accumulator chamber 54 of the bladder type accumulator 52 communicates with the pump chamber 34. The discharge valve 42 is pressed against the ball 46 by the large spring force of the compression coil spring 48, and is kept closed. The operating rod 50 is attached to the tip of the plunger 20 and reciprocates integrally with the plunger 20 to come into contact with the ball 46 of the discharge valve 42 near the top dead center of the plunger 20 to move the ball 46 into a compression coil spring. Push against the spring force of 48 to force the discharge valve 42 to open.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a reciprocating pump that can increase the pressure of liquid that is intermittently discharged.

[0002]

[Prior art]

 International Publication No. WO91 / 07077 discloses that spray liquid is intermittently sprayed from a nozzle onto a lawn at high pressure to form through holes for air rates on the grass. In the high-pressure liquid injection device disclosed in International Publication WO 91/07077, an accumulator is arranged between the portion passing through the discharge valve of the pump and the intermittent valve, and the discharge liquid of the pump is accumulated in the accumulator to form an intermittent valve. Controls the connection between the accumulator and nozzle to perform intermittent injection of high-pressure liquid.

[0003]

[Problems to be solved by the device]

 In the high-pressure liquid injection device of International Publication WO91 / 07077, an intermittent valve is indispensable for performing intermittent injection, and the configuration becomes complicated.

Therefore, Japanese Patent Application No. 5-67342 discloses that intermittent spraying is performed from a nozzle by omitting an intermittent valve by utilizing intermittent discharge of a reciprocating pump.

In a normal reciprocating pump, since the liquid is continuously discharged while the volume of the pump chamber is decreasing, there is a limit in increasing the injection pressure from the nozzle.

Japanese Laid-Open Patent Publication No. 63-1771 discloses a reciprocating pump in which an operating rod capable of contacting a discharge valve is attached to the tip of a reciprocating member. The valve simply regulates the unidirectional flow of liquid from the pump chamber to the discharge port, and during normal operation when the discharge valve is not stuck, the discharge valve moves during the discharge stroke of the reciprocating member. , It is open all the time and has no function to increase the pressure of the discharged liquid.

An object of the present invention is to provide a reciprocating pump that can increase the pressure of liquid that is intermittently discharged.

[0008]

[Means for Solving the Problems]

 The invention will be described using the reference numerals of the drawings corresponding to the embodiments. The reciprocating pump (10) of the present invention has the following components (a) to (d). (A) A reciprocating member (20) that reciprocates to increase or decrease the volume of the pump chamber (34) (b) An accumulator (52) that directly communicates with the pump chamber (34), and (c) a valve body (46). The discharge valve (42) (which controls the connection between the pump chamber (34) and the discharge port (30) is provided with a biasing means (48) that biases the valve body (46) in the closing direction and holds it closed. d) The reciprocating member (20) is reciprocally moved integrally to push the valve body (46) against the biasing means (48) near the top dead center of the reciprocating member (20) to discharge valve (42). Operation member for forcibly opening (50)

[0009]

[Action]

 The pump chamber (34) increases or decreases in volume as the reciprocating member (20) reciprocates. In the first half of the stroke in which the reciprocating member (20) proceeds from bottom dead center to top dead center, the operating member (50) is still separated from the discharge valve (42), and the discharge valve (42) is The urging means (48) presses the (46) in the closing direction to keep it closed. As a result, the liquid (92) in the pump chamber (34) enters the accumulator (52) and accumulates pressure as the volume of the pump chamber (34) decreases.

When the reciprocating member (20) has sufficiently advanced to the tip side of the pump chamber (34) and is near the top dead center, the operating member (50) causes the valve body (46) of the discharge valve (42) to move. ), The valve body (46) is pushed and displaced in the opening direction against the biasing means (48), whereby the discharge valve (42) is forcibly opened. The high pressure liquid (92) in the accumulator (52) is discharged from the discharge valve (42) through the pump chamber (34).

[0011]

【Example】

 The present invention will be described below with reference to the embodiments shown in the drawings. 1 and 2 are vertical sectional views of the plunger pump 10 when the plunger 20 is at the bottom dead center and the top dead center. The crankcase 12 is mounted and supported on the rails 14 and fixed to the rails 14 with bolts 16. The crankshaft 18 (FIG. 3) is rotatably supported by the crankcase 12 at both ends and integrally includes a circular crankpin 19 whose center is offset from the center line of the crankshaft 18. The plunger 20 has a crosshead 21 at the base end, and the crosshead 21 is inserted into the guide 22 of the crankcase 12 and guided by the guide 22 in the direction of the center line of the guide 22. The connecting rod 24 is fitted to the peripheral portion of the crank pin 19 at the large end portion, is rotatably connected to the cross head 21 via the cross pin 25 at the small end portion, and is rotated as the crank shaft 18 rotates. Reciprocate the plunger 20.

The manifold 26 is joined to the front end side of the crankcase 12, and has a suction port 28 in the lower part. The discharge-side connecting member 32 is screwed to the tip of the manifold 26 and has a discharge port 30. The pump chamber 34 is formed in the manifold 26 and communicates with the suction port 28 and the discharge port 30. The suction valve 36 has a ball 38 and a compression coil spring 40 that urges the ball 38 toward the suction port 28 side. The suction valve 36 is installed in a built-in hole between the suction port 28 and the pump chamber 34 and has a plug 41. It is prevented from coming off by allowing the unidirectional flow of water 92 (FIG. 5) from the suction port 28 to the pump chamber 34. The valve chamber 44 communicates with the pump chamber 34 through the communication hole 47 on one end side, is blocked by the discharge side connecting member 32 on the other end side, and communicates with the discharge port 30 of the discharge side connecting member 32. There is. The discharge valve 42 is arranged in the valve chamber 44, and has a ball 46 and a compression coil spring 48 that presses the ball 46 against the communication hole 47 with a sufficiently large spring force.

The operating rod 50 is screwed to the tip of the plunger 20 with its center line aligned with the center of the plunger 20, protrudes toward the discharge valve 42, and has a diameter smaller than the diameter of the communication hole 47. The bladder type accumulator 52 has an accumulator chamber 54 that is attached to the upper portion of the manifold 26 and communicates with the pump chamber 34, and a bladder 56 that is filled with high-pressure air and expands and contracts according to the hydraulic pressure in the accumulator chamber 54. is doing.

The seal retainer 58 is fitted into the joint between the crankcase 12 and the manifold 26, and retains the oil seals 60 and 62 on the inner peripheral portions on both sides in the axial direction. The oil seals 60 and 62 are in sliding contact with the peripheral portion of the plunger 20 on the inner peripheral side and hold the seal against the lubricating oil in the crankcase 12. The V-packing 64 is pressed by the seal retainer 58 to the step portion on the inner peripheral side of the manifold 26, swells in the radial direction, and slidably contacts the peripheral portion of the plunger 20 on the inner peripheral side to seal the pump chamber 34. Hold.

FIG. 3 shows the relationship between the discharge pressure of the plunger pump 10 and the crank angle. In FIG. 3, the chain double-dashed line shows the pressure in the pump chamber of the conventional general plunger pump. The operation of the plunger pump 10 will be described with reference to FIG.

With the rotation of the crankshaft 18, the crankpin 19 rotates so that its center moves on a circle centered on the centerline of the crankshaft 18. The connecting rod 24 transmits the rotational movement of the crank pin 19 to the cross head 21, and the plunger 20 reciprocates.

In the process in which the plunger 20 moves from the top dead center toward the bottom dead center, the volume of the pump chamber 32 increases. In addition, the operating rod 50 separates from the ball 46 of the discharge valve 42 when the plunger 20 slightly moves from the top dead center to the bottom dead center. As a result, the discharge valve 42 is closed by the ball 46 being pressed by the compression coil spring 48 into the communication hole 47, closing the communication hole 47, and causing a negative pressure in the pump chamber 34. The suction valve 36 is opened. As a result, water 92 (FIG. 5) is sucked into the pump chamber 34 from the suction port 28 through the suction valve 36.

During the stroke in which the plunger 20 moves from the bottom dead center to the top dead center, at the crank angle at which the plunger 20 is sufficiently far from the vicinity of the top dead center, the tip of the operating rod 50 is positioned at the ball of the discharge valve 42. Without reaching 46, the discharge valve 42 presses the ball 46 into the communication hole 47 by the large spring force of the compression coil spring 48 to close the communication hole 47 and keep it closed. Since the volume of the pump chamber 34 decreases, the suction valve 36 closes and the water 92 in the pump chamber 34 is introduced into the accumulator chamber 54 of the bladder type accumulator 52. The bladder 56 reduces in size with the introduction of the water 92 into the accumulator chamber 54, and stores the pressure of the water 92 in the accumulator chamber 54.

When the plunger 20 is sufficiently close to the top dead center, the tip portion of the operating rod 50 passes through the communication hole 47 and comes into contact with the ball 46 of the discharge valve 42. The discharge valve 42 is forcibly opened by pushing it against the spring force and separating it from the communication hole 47. As a result, the high-pressure water 92 stored in the accumulator chamber 54 of the bladder type accumulator 52 is discharged from the discharge valve 42 to the discharge port 30 at once through the pump chamber 34 and the communication hole 47.

FIG. 4 is a definition diagram of each symbol. The definition of each symbol is as follows. S: The diameter of the circular locus drawn by the center of the large end of the connecting rod 24, which is equal to the stroke amount of the plunger 20. θ: Absolute value of crank angle when the operating rod 50 contacts the ball 46 (top dead center of the plunger 20 is crank angle = 0 °). ΔS: Amount of displacement of the ball 46 at the top dead center of the plunger 20. Using these codes, t is defined by the following equation. t = 2θ / 360 = θ / 180 = (1/180) · sec {1− (2 · ΔS) / S} According to the above equation, for example, if S = 30 mm and ΔS = 3 mm, then t = 1/4 .88, and the crank angle at which the water 92 is discharged from the plunger pump 10 is about 1/5 that of the conventional plunger pump.

FIG. 5 is a configuration diagram of a high-pressure liquid injection device 80 including the plunger pump 10. The high-pressure liquid injection device 80 is mounted on a self-propelled vehicle traveling on the lawn 106. The rotational power of the engine 82 is transmitted to the crankshaft 18 via the V pulley 84, the V belt 86, and the V pulley 88, and rotationally drives the crankshaft 18. The tank 90 stores water 92, and the lower portion thereof is connected to the suction port 28 of the plunger pump 10 via the suction pipe line 94. The discharge port 30 is connected to the discharge line 96, and the safety valve 98 opens when the hydraulic pressure in the discharge line 96 becomes abnormally high, so that the water 92 in the discharge line 96 passes through the return line 100. Return to tank 90. The nozzle row 102 is composed of a plurality of nozzles 104 whose nozzle holes are directed to the lawn 106 and which are horizontally arranged in a row in a horizontal direction, and are connected to the discharge pipeline 96.

With the operation of the plunger pump 10, the water 92 in the tank 90 is sucked into the plunger pump 10 and accumulated in the bladder type accumulator 52. Then, when the plunger 20 of the plunger pump 10 reaches the vicinity of the top dead center in the process of proceeding from the bottom dead center to the top dead center, the water 92, which has been accumulated in the bladder accumulator 52, is discharged from the discharge port 30 at once. It is discharged to the outlet pipe 96 and is ejected at high pressure from each nozzle 104 of the nozzle row 102 toward the lawn 106. As a result, an air through hole is formed in the ground 108 below the lawn 106. In this high-pressure liquid injection device 80, the intermittent valve between the plunger pump 10 and the nozzle 104 is omitted, and the structure is simplified. When a pesticide or fertilizer liquid is used instead of the water 92, the lawn 106 can be simultaneously controlled and fertilized while forming the ventilation hole in the ground 108, thus improving the work efficiency.

[0023]

[Effect of device]

 In this device, when the reciprocating member is near the top dead center, the discharge valve is forcibly opened to discharge the high-pressure liquid accumulated in the accumulator from the pump chamber through the discharge valve all at once. Therefore, the pressure of the liquid intermittently ejected from the reciprocating pump can be greatly increased.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a plunger pump when the plunger is at bottom dead center.

FIG. 2 is a vertical sectional view of the plunger pump when the plunger is at the top dead center.

FIG. 3 is a graph showing a relationship between a discharge pressure of a plunger pump and a crank angle.

FIG. 4 is a definition diagram of each symbol.

FIG. 5 is a configuration diagram of a high-pressure liquid injection device including a plunger pump.

[Explanation of symbols]

 10 Plunger pump (reciprocating pump) 20 Plunger (reciprocating member) 30 Discharge port 34 Pump chamber 42 Discharge valve 46 Ball (valve body) 48 Compression coil spring (biasing means) 50 Operation rod (operating member) 52 Bladder type accumulator ( Accumulator) 92 Water (liquid)

Claims (1)

[Scope of utility model registration request] 1. A reciprocating member (20) for reciprocating to increase or decrease the volume of a pump chamber (34), (b) an accumulator (52) directly communicating with the pump chamber (34), (c) ) A valve body (46) and a biasing means (48) for biasing the valve body (46) in the closing direction to hold the valve body (46) closed are provided to connect the pump chamber (34) and the discharge port (30). The discharge valve (42) to be controlled, and (d) the reciprocating member (20) is reciprocated integrally with the reciprocating member (20) to urge the valve body (46) near the top dead center. A reciprocating pump comprising: an operating member (50) forcibly opening the discharge valve (42) by pushing against the means (48).