JPH04105976U - Forced valve type piston pump - Google Patents

Abstract

(57) [Summary] [Purpose] In the forced valve type piston pump 10, while suppressing the increase in the sliding resistance of the piston rod 20 and the wear of the seal packing 24, The sealing performance of the seal packing 24 is ensured against water hammer action on the seal packing 24. [Structure] The seal packing 24 that seals the base end side of the suction space 61 in the axial direction of the piston rod 20 is provided with a V groove 74 on the suction space 61 side, and the lip 72 to the piston rod 20 is formed by expanding the V groove 74. The pressing force is increased. The compression coil spring 78 is compressed between the valve body 28 and the male adapter 76, and generates a biasing force in the direction of axial expansion, so that the male adapter 76
into the V-groove 74.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to a forced valve type piston pump installed in power sprayers, etc. Otherwise, the suction liquid flows from the suction space through the circumference of the piston rod toward the proximal end of the piston rod. Forced valve type that can improve the sealing performance of the seal packing to prevent leakage. This relates to piston pumps.

0002

[Conventional technology]

In the forced valve type piston pump of Utility Model Publication No. 64-53476, the piston rod is , is inserted into the inner peripheral edge of the seal packing, passes through the suction space, and enters the pump chamber. The sealing pressure of the seal packing is due to the elasticity of the seal packing inward in the radial direction. It is caused only by force.

0003 Japanese Utility Model Application Publication No. 56-37755 discloses that a plurality of V packings are inserted into male and female parts from both sides. A compression coil spring is used to connect a plurality of V Press the packing in the axial direction to maintain a constant sealing pressure despite the wear of the V-packing. Disclose that you will secure.

0004

[Problem that the idea aims to solve]

In forced valve piston pumps, the piston rod moves toward the proximal end during the suction stroke. When moving, the circumference of the piston rod is moved by the valve body of the suction valve, which is fixed to the piston rod. The liquid near the piston rod receives force toward the proximal end of the piston rod, and the liquid near the A water hammer effect occurs. Forced valve type piston disclosed in Utility Model Publication No. 64-53476 In ton pumps, the sealing pressure of the seal packing is insensitive to water hammer action. It becomes sufficient that liquid tends to leak through the seal packing.

[0005] In Japanese Utility Model Application Publication No. 56-37755, the sealing pressure is increased by a compression coil spring. However, when applying this structure to a forced valve type piston pump, the suction line Seal pressure during the discharge stroke without worrying about leakage due to water hammer. This increases the sliding resistance of the piston rod and also increases the seal resistance. This will accelerate the wear of the packing.

[0006] The purpose of this invention is to suppress the sliding resistance of the piston rod and the wear of the seal packing. At the same time, it is necessary to ensure good sealing performance of the seal packing against water hammer action. An object of the present invention is to provide a forced valve type piston pump that can

[0007]

[Means to solve the problem]

This invention will be explained using reference numerals in the drawings that correspond to the embodiments. The forced valve type piston pump (10), which is the premise of this invention, has a piston rod (20) that The pump chamber (62) is reached through the space (61), and the suction valve (26) is fixed to the piston rod (20). The valve body (28) is loosely fitted into the piston rod (20) on the tip side of the valve body (28). It has a valve seat (30). Also, the seal packing (24) is attached to the axial direction of the piston rod (20). With respect to the direction, slide the inner circumferential side on the proximal side of the suction space (61) to the circumference of the piston rod (20). are in contact with each other.

[0008] The forced valve type piston pump (10) of this invention has (a) a suction space (61) side; Seal packing (24) with V groove (74) and (b) V groove (74) that can be freely expanded into V groove (74). (c) The male adapter (76) to be fitted, and (c) the valve body (2) with a biasing force in the direction of axial extension. 8) and a biasing member (78) that is compressed between the male adapter (76) and the male adapter (76).

[0009]

[Effect]

During the discharge stroke, the piston rod (20) moves towards the pump chamber (62) and closes the valve of the suction valve (26). Since the body (28) also moves in the direction away from the seal packing (24), the volume of the suction space (61) decreases. increases, and the pressure in the suction space (61) is low. Also, the biasing member (78) is in the extended state. Then, the biasing member (78) presses the male adapter (76) into the V-groove (74) of the seal packing (24). Power decreases. Therefore, the V groove (74) is in a contracted and closed state, and the seal packing (24) The force pushing the inner circumferential side toward the piston rod (20) is small, and the seal packing (24) is The air pressure is also low.

0010 On the other hand, during the suction stroke, the piston rod (20) moves toward the proximal end, and the suction valve (2 The valve body (28) of 6) moves toward the seal packing (24), so it moves against the seal packing (24). A water hammer effect occurs due to the fluid in the suction space (61). On the other hand, the biasing member (7 8) is in the contracted state, the biasing member (78) pushes the male adapter (76) into the sealing packing (24). The force pressing against the V-groove (74) increases. Therefore, the V-groove (74) is widened and the seal The force that presses the inner circumferential side of the packing (24) toward the piston rod (20) increases, and the sealing pad The sealing pressure of the seal (24) increases.

[0011]

【Example】

This invention will be described below with reference to embodiments shown in the drawings. FIG. 2 is a longitudinal sectional view of the forced valve type piston pump 10. Crankcase 11, intake The side manifold 12, cylinder pipe 14, and discharge side manifold 16 are arranged horizontally. They are arranged in that order along the line, and adjacent ones are joined and fixed to each other. inhalation The pipe 18 is connected to the lower part of the suction side manifold 12 by screwing. piston rod 20 extends from the crankcase 11 to the cylinder pipe 14, and Power is transmitted from a crankshaft (not shown) in the case 11 to reciprocate. O The oil seal 22 is attached to the crankshaft so that the piston rod 20 can slide on its inner peripheral surface. It is fixed to the case 11 and keeps the inside of the crankcase 11 oil-tight. Seal pack The piston rod 24 is attached to the suction side manifold so that the piston rod 20 can slide on its inner peripheral surface. It is fixed to the end of the crankcase 11 side of the door 12 to ensure liquid tightness inside the suction side manifold 12. Hold.

0012 The suction valve 26 includes a circular plate-shaped valve body 28 fixed to the piston rod 20, and a valve body 28 that is fixed to the piston rod 20. The valve seat 30 is disposed on the tip side of the piston rod 20 and is loosely fitted into the piston rod 20. are doing. The piston rod 20 includes a valve body 28, a valve seat 30, a collar 32, and a stopper from its base end. The capper 34 and spring washer 36 are fitted in order, and the hexagonal nut 38 is attached to the tip of the piston rod 20. The parts are screwed together and tightened in the axial direction to fix them. Valve body 28 and stopper 34 The amount of relative movement of the valve seat 30 to the piston rod 20 between It is considered to be less than the amount of backward movement. The stopper 34 has a plurality of through holes 40 passing through it in the axial direction. The piston packing 42 is fitted around the outer periphery of the valve seat 30 and It is possible to slide on the inner circumference of the pulley 14. The O-rings 44 and 46 are the shaft of the cylinder pipe 14. It is fitted into the annular groove on the outer periphery of both ends of the cylinder pipe 14 and the suction side manifold. The joints with the door 12 and the discharge side manifold 16 are kept liquid-tight.

[0013] The discharge valve 48 is disposed within the discharge side manifold 16 and is connected to the cylinder pipe at the periphery. The valve seat 50 is sandwiched between the valve 14 and the discharge side manifold 16, and the valve seat 50 is A valve body 52 that can be seated from the opposite side of the stone rod 20, and a valve body 52 that accommodates this valve body 52 and is attached to the periphery. It is sandwiched together with the valve seat 50 between the cylinder pipe 14 and the discharge side manifold 16. The valve sack 54 is fixed to the valve sack 54 to limit the movement range of the valve body 52. It has a stopper 56 and a compression coil spring 58 that presses the valve body 52 against the valve seat 50.

[0014] The suction port 60 is formed within the suction pipe 18 and is penetrated by the piston rod 20. It communicates with the suction space 61 in the suction side manifold 12. Pump chamber 62 is a cylinder It is formed between the suction valve 26 and the discharge valve 48 in the pipe 14, and the discharge port 64 is connected to the discharge valve 48. It is formed in the discharge side manifold 16 on the more downstream side.

[0015] During the suction stroke when the piston rod 20 is far away from the discharge valve 48, the piston packing on the valve seat 30 There is fluid resistance in the cylinder 42 and sliding resistance between the piston packing 42 and the inner surface of the cylinder pipe 14. Since the resistance acts, the valve seat 30 is pressed against the periphery of the stopper 34, and the valve body 28 and the valve seat There will be a gap between 30 and 30. In addition, since the volume of the pump chamber 62 increases, the pump chamber 62 The pressure of the fluid (generally water) in the discharge valve 48 is small, and the valve body 52 is compressed by a compression coil. is pressed against the valve seat 50 by a spring 58. Therefore, the fluid in the suction port 60 passes from the suction space 61 to the outside of the valve body 28 of the suction valve 26 to form the gap between the valve body 28 and the valve seat 30. From there, the radial gap between the collar 32 and the valve seat 30 and the stock It flows into the pump chamber 62 through the through hole 40 of the pump 34 .

[0016] During the discharge stroke in which the piston rod 20 moves toward the discharge valve 48, a pump is applied to the valve seat 30 of the suction valve 26. Since a large pressure is applied from the suction chamber 62 side, the valve seat 30 is pressed against the valve body 28, and the suction Communication between the space 61 and the pump chamber 62 is cut off. Also, the volume of the pump chamber 62 decreases. Then, the fluid pressure in the pump chamber 62 increases, and the valve body 52 in the discharge valve 48 closes to the compression coil spring. It is separated from the valve seat 50 against the force 58. Therefore, the fluid in the pump chamber 62 is discharged from the discharge valve It exits to the discharge port 64 via 48.

[0017] In the forced-valve piston pump 10 equipped with such a forced-valve suction valve, the piston Since the suction valve 26 is automatically opened and closed by the reciprocating movement of the pump rod 20, the rotation of the pump and In particular, the followability of the suction valve 26 at high speeds is improved, and the flow from the suction valve 26 to the discharge valve 48 is improved. Since the fluid flows in almost the same direction in the range of The inertia of the fluid is used for packing, and the volumetric efficiency of the forced valve type piston pump 10 is high. It becomes.

[0018] FIG. 1 is a structural diagram of the area centered on the suction space 61. Seal packing 24 is A suction space 61 on the tip side and an intermediate chamber 66 on the proximal side are partitioned in the axial direction of the stone rod 20. , has lips 70 and 72 on the intermediate chamber 66 and suction space 61 sides, respectively, on the inner peripheral side. The piston rods 70 and 72 are in sliding contact with the circumference of the piston rod 20. Packing foot 68 is medium The seal packing 24 is fixed to the stepped portion of the suction side manifold 12 from the interchamber 66 side. The V groove 74, which is annular and has a V-shaped cross section, is formed on the side surface of the seal packing 24 on the suction space 61 side. The inner half in the radial direction is divided by a lip 72. male adapter 76 , the convex section having a larger angle than the V-groove 74 is fitted into the V-groove 74. compression coil spring 78 is locked to the valve body 28 and the male adapter 76 at both ends, and extends in the axial direction. Generates urging force.

[0019] The sealing action of the seal packing 24 will be explained. During the discharge stroke, the piston rod 20 moves toward the pump chamber 62 and the valve body 28 of the suction valve 26 also moves. Since it moves in the direction away from the seal packing 24, the volume of the suction space 61 increases in the axial direction. However, the pressure in the suction space 61 is low. Also, since the compression coil spring 78 is in an extended state, , the force with which the compression coil spring 78 presses the male adapter 76 against the V-groove 74 of the seal packing 24 is descend. Therefore, the V groove 74 is in a contracted and closed state, and the lip 72 of the seal packing 24 The force pushing the piston rod 20 toward the piston rod 20 is small, and the sealing pressure of the seal packing 24 is also low. It has become.

[0020] On the other hand, during the suction stroke, the piston rod 20 moves toward the crankcase 11, The valve body 28 of the suction valve 26 moves toward the seal packing 24, so it A water hammer effect occurs due to the liquid in the suction space 61. On the other hand, the compression coil Since the spring 78 is in the contracted state, the compression coil spring 78 seals the male adapter 76. The force pressing against the 24 V grooves 74 increases. Therefore, the V-groove 74 is expanded and the seal pad The force that presses the lip 72 of the packing 24 toward the piston rod 20 increases, and the seal packing The sealing pressure of the tube 24 increases.

[0021]

[Effect of the idea]

This design uses a seal pad that seals the proximal end of the piston rod against the suction space. Kin is equipped with a V-groove on the suction space side, and the expansion of the V-groove applies sealing pressure to the piston rod. At the same time, the distance between the valve body of the suction valve and the seal packing is reduced. A biasing member with increasing force presses the male adapter into the V-groove. Therefore, In the suction stroke where the data hammer action occurs, the sealing pressure of the seal packing is increased. , the seal pad is used in the discharge stroke to ensure sealing performance and to avoid water hammer action. By reducing the sealing pressure of the seal, it suppresses the wear of the seal packing and prevents the sliding of the piston rod. Dynamic resistance can be reduced.

[Brief explanation of drawings]

FIG. 1 is a structural diagram of an area centered on an inhalation space.

FIG. 2 is a longitudinal sectional view of a forced valve type piston pump.

[Explanation of symbols]

10 Forced valve type piston pump 20 Piston rod 24 Seal packing 26 Suction valve 28 Valve body 30 Valve seat 61 Suction space 62 Pump room 74 V groove 76 Male adapter 78 Compression coil spring (biasing member)

Claims (1)

[Scope of utility model registration request] Claim 1: The piston rod (20) passes through the suction space (61) and reaches the pump chamber (62), and the suction valve (26) is connected to the piston rod.
(20), a valve seat (30) that is loosely fitted to the piston rod (20) on the distal end side of the valve body (28), and has a seal packing (24). is in sliding contact with the circumference of the piston rod (20) on the inner circumferential side on the proximal end side of the suction space (61) in the axial direction of the piston rod (20), V groove on the suction space (61) side
(74); a male adapter (76) that fits into the V-groove (74) so that the V-groove (74) can be freely expanded;
A biasing member (78) having a biasing force in a direction extending in the axial direction and compressed between the valve body (28) and the male adapter (76). Valve type piston pump.