JP3500595B2 - Forced valve piston pump - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forced valve type piston pump equipped in a washing machine, a power sprayer or the like, and more particularly to a forced valve type piston pump with improved fluid flow in a suction valve. .

[0002]

2. Description of the Related Art In a forced valve type piston pump, a stopper with a passage and a valve seat are fixed to the front end of a piston rod with a predetermined interval in relation to the front end side and the base end side, respectively, and a valve body is connected to a cylinder. A sliding piston packing is mounted on the outer peripheral side, and it is loosely fitted to the piston rod between the stopper with a passage and the valve seat in the axial direction so that it comes into contact with the stopper with a passage and the valve seat during the intake stroke and the discharge stroke, respectively. It has become.

FIG. 5 shows a valve body 40 in a conventional forced valve type piston pump (eg, Japanese Utility Model Laid-Open No. 60-34576).
FIG. The same elements as those of the embodiment of the present invention described later are designated by the same reference numerals, and the main points will be described. The valve body 40 has a clearance 80 between it and the intake manifold 12, and the seating surface 82 with the valve seat 28 is a flat surface.
During the suction stroke, the valve element 40 opens a predetermined gap with the valve seat 28. The liquid that has passed radially outside the valve seat 28 enters the escape 80 or the valve body 4 as shown by the flow F '.
It collides with the seating surface 82 of 0, and after that, the direction is reversed, collides with the valve seat 28, changes the direction again toward the tip end of the piston rod 22, and advances toward the pump chamber.

[0004]

In the conventional forced valve type piston pump, the suction valve 46 merely performs the opening / closing operation during the suction stroke and the discharge stroke, and does not consider the liquid flow at the time of opening. Didn't. Therefore, the liquid is
While making a large bend, it advances, leading to an increase in inflow resistance and an increase in noise.

Incidentally, in FIG. 2 of Japanese Utility Model Laid-Open No. 60-34576, the upstream portion of the valve seat of the intake valve is formed into a taper,
It smoothes the flow of liquid on the upstream side of the valve seat, but does not suggest any improvement in the flow of liquid between the valve seat and the valve body in the intake valve.

It is an object of the present invention to provide a forced valve piston pump which improves the flow of liquid between the valve seat and the valve body in the intake valve.

[0007]

In the forced valve type piston pump (10) of the present invention, a stopper (32) with a passage and a valve seat (2) are provided.
8) is fixed to the front end of the piston rod (22) with a predetermined interval in relation to the front end side and the base end side. Disc (4
(0) is fitted with a piston packing (42) that slides on the cylinder (14) on the outer peripheral side, and the piston rod (22) is free to move axially between the stopper (32) with passage and the valve seat (28). It is fitted so as to come into contact with the stopper (32) with the passage and the valve seat (28) during the intake stroke and the discharge stroke, respectively. In such a forced valve type piston pump (10), the suction fluid guide member (44)
Is arranged on the suction side of the valve body (40) so as to cover the radial range from the peripheral portion of the end surface of the valve body (40) to the inner surface of the cylinder (14). The suction-side portion of the suction fluid guide member (44) projects toward the upstream side in the radial direction, and collides with the fluid that passes through the radial outside of the valve seat (28) during the suction stroke. (66).

When the valve body (40) is opened, the fluid passing through the outside of the valve seat (28) in the radial direction in the axial direction of the piston rod (22) must enter the relief portion of the valve body (40). Without suction fluid guide member
The fluid is received by the fluid receiving portion (66) of (44), the reversal of the direction is suppressed, and flows inward in the radial direction along the fluid receiving portion (66). As a result, the fluid that collides with the valve body (40) is prevented from violently colliding with the subsequent fluid or colliding with the valve seat (28), and is prevented from flowing by being greatly bent, and the fluid flow is smoothed. .
As a result, it is possible to reduce suction resistance and noise.

According to the forced valve type piston pump (10) of the present invention, the suction fluid guide member (44) is made of an elastic material.

The valve body (40) is a valve seat when switching from open to closed.
Although it collides with (28), it is a suction fluid guide member made of an elastic material.
(44) is interposed between the valve body (40) and the valve seat (28), and the valve seat (28)
The collision of the valve body (40) with the This allows the valve seat (28)
The collision noise caused by the collision of the valve element (40) with the vehicle is reduced, and the damage caused by the collision is suppressed.

According to the forced valve type piston pump (10) of the present invention, the suction fluid guide member (44) includes the valve body (4) during the discharge stroke.
It has a shrinkage margin that ensures that 0) sticks to the valve seat (28).

When the valve body (40) is closed, the suction fluid guide member (44) is elastically compressed by a contraction amount due to the sandwiching pressure between the valve seat (28) and the valve body (40). The valve body (40) can be appropriately brought into close contact with the valve seat (28), and interference with the valve body (40) due to the elastic material can be eliminated.

According to the forced valve type piston pump (10) of the present invention, the suction fluid guide member (44) is not connected to the valve body (40) and is axially attached to the piston rod (22). It can be displaced relative to it.

Even if the suction fluid guide member (44) is not connected to the valve body (40), the valve seat (28) is used by the valve body (40) during the discharge stroke of the forced valve piston pump (10). Was pushed to
Also, during the intake stroke of the forced valve piston pump (10),
Due to the collision of the liquid flowing in on the radially outer side of the valve seat (28), the liquid is pushed toward the valve seat (28) and moves axially together with the valve seat (28). Since it is possible to omit connecting the suction fluid guide member (44) to the valve body (40), the manufacturing cost is reduced.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a vertical cross-sectional view of the main part of the forced valve type triple piston pump 10. The forced valve type triple piston pump 10 is installed in a washing machine, a power sprayer, or the like, is arranged in a line in the axial direction of a crankshaft (not shown), and is driven by a common crankshaft. Is made up of. The intake manifold 12, the cylinder 14, and the discharge manifold 16 are arranged in order in the horizontal direction from a crankcase (not shown), and are horizontally tightened to the crankcase by predetermined tightening bolts. The connecting pipe 18 is interposed at the joint between the intake manifold 12 and the cylinder 14 and maintains a seal between them. The connecting pipe 20
Intervenes at the joint between the cylinder 14 and the discharge manifold 16,
Hold the seal between the two. Intake manifold space 26
Is formed inside the suction manifold 12 and communicates with a common suction port (not shown) of the forced valve type triple piston pump 10. The piston rod 22 passes through the intake manifold 12 from the crankcase along the center line of the cylinder 14, reaches the cylinder 14, and is reciprocally driven by the crankshaft in the crankcase. The low-pressure seal 24 is inserted in the base end side of the intake manifold 12 and slidably contacts the piston rod 22 on the inner peripheral side to prevent liquid leakage from the intake manifold internal space 26. A valve seat 28, a collar 30, and a stopper 32 with a through hole are fitted to the tip end portion of the piston rod 22 in order from the base end side, and the stopper 32 with a through hole has a plurality of through holes 34. There is. Instead of the through hole 34, the through hole stopper 32 may be formed with a groove having a predetermined depth. The washer 38 is applied to the tip side of the stopper 32 with a through hole, and the nut 36 is screwed to the tip portion of the stopper 32 with a through hole, and the valve seat 28, the collar 30, and the stopper with a through hole are inserted through the washer 38. 32 is pushed toward the base end. Disc 40
The piston packing 42, which is in sliding contact with the inner surface of the cylinder 14, is fitted on the outer peripheral side, and is arranged between the valve seat 28 and the stopper 32 with a through hole with a predetermined gap between the piston packing 42 and the collar 30 in the radial direction. . The liquid guide 44 is fixed to an end portion of the valve body 40 on the valve seat 28 side, and the valve seat 28 and the valve body 40 form a suction valve 46.

The pump chamber 48 is formed in the range of the connecting pipe 20 and the cylinder 14 on the tip side of the stopper 32 with a through hole. The discharge valve 50 is provided on the front end side of the pump chamber 48 with its center line aligned with the center line of the pump chamber 48, and its peripheral edge portion is sandwiched between the discharge manifold 16 and the connecting pipe 20 together with the compression coil spring 58. Valve seat 52 and valve seat 56
52 includes a valve body 54 that can be seated freely, and a compression coil spring 58 that biases the valve body 54 toward the valve seat 52. The discharge manifold inner space 60 is formed in the discharge manifold 16 and communicates with a common discharge port (not shown) of the forced valve type triple piston pump 10. The discharge valve 50 allows the liquid to flow in one direction from the pump chamber 48 to the space 60 in the discharge manifold.

FIG. 4 is an enlarged view of the vicinity of the liquid guide 44, and FIGS. 1 and 2 are detailed views of the vicinity of the suction valve 46 when the suction valve 46 is opened and closed, respectively. Mainly in FIG.
The liquid guide 44 is made of an elastic material and is fixed to the valve body 40 so as to cover the radial range from the peripheral portion of the upstream end surface of the valve body 40 to the inner surface of the cylinder 14, and the concave curved surface 66 of the liquid guide 44. Is a concave curved surface in a vertical cross-sectional view, and extends outward in the radial direction toward the upstream side. Seating surface 68 is a liquid guide 44
It is the upstream end face of the valve element 40 that is exposed without being covered by the valve, and is a flat surface that is perpendicular to the axial direction like the end face of the valve seat 28. The radial inner end of the concave curved surface 66 of the liquid guide 44 projects toward the upstream side of the seating surface 68 by the contraction margin δ when the suction valve 46 is opened, but when the suction valve 46 is closed, this The seating surface 68 is elastically compressed in the axial direction by the shrinkage allowance δ.
Or slightly retracted inward to ensure that the seating surface 68 adheres to the valve seat 28.

In FIGS. 1 and 2, the valve body 40 is also
On the inner peripheral side, chamfers 70 and 72 are provided at the ends of the valve seat 28 side and the through hole stopper 32 side, respectively. The maximum diameter of the chamfer 72, that is, the diameter of the outer end is equal to or smaller than the outer diameter of the through hole 34, and is preferably equal to the outer diameter of the through hole 34.
The peripheral portion of the end surface of the valve seat 28 on the valve body 40 side is a radius 74.

The operation of the forced valve type triple piston pump 10 will be described. During the suction stroke, the piston rod 22 moves in the proximal direction, and the volume of the pump chamber 48 increases. The valve body 40 is
Due to the negative pressure on the pump chamber 48 side, the frictional force between the inner surface of the cylinder 14 and the piston packing 42, and the like, the piston rod 22 moves relative to the stopper 32 with the through hole, separates from the valve seat 28, and Contact the stopper 32 with a hole. As a result, the intake valve 46 and the discharge valve 50 are opened and closed, respectively.
The liquid in the suction manifold inner space 26 is pumped through the outer peripheral side of the valve seat 28, between the valve seat 28 and the valve body 40, the inner peripheral side of the valve body 40, and the through hole 34 of the stopper 32 with the through hole. It flows into the chamber 48.

In the discharge stroke, the piston rod 22 moves toward the tip, and the volume of the pump chamber 48 decreases. The valve body 40 is seated against the piston rod 22 due to increased pressure on the pump chamber 48 side.
It moves relative to 28 and separates from the valve seat 28,
Abut on the stopper 32 with a through hole. This allows the intake valve 46
The discharge valve 50 is closed and opened, and the liquid in the suction manifold internal space 26 is discharged to the discharge manifold internal space 60 via the discharge valve 50.

As shown by F in FIG. 1, the liquid flow near the suction valve 46 during the suction stroke is such that the liquid passing radially outside the valve seat 28 collides with the concave curved surface 66 of the liquid guide 44. To do. The concave curved surface 66 suppresses the colliding liquid from being reflected to the upstream side and prevents the colliding liquid from colliding with the end surface of the valve seat 28 on the valve body 40 side. The liquid that has collided with the concave curved surface 66 is guided along the surface of the concave curved surface 66 inward in the radial direction and toward the tip side in the axial direction. The radius 74 contributes to the smooth transition of the liquid passing near the periphery of the valve seat 28 inward in the radial direction immediately after passing the valve seat 28. Chamfer 70 has a concave curved surface 66
And, the liquid flowing inward in the radial direction along the seating surface 68 contributes to smoothly changing the direction to the axial leading end side. The total area of the through holes 34 is sufficiently large, and is, for example, not less than the flow passage cross-sectional area in the inner surface of the cylinder of the valve body 40. When the total cross-sectional area of the through hole 34 is small, the liquid is squeezed in the through hole 34,
Although it causes cavitation in the pump chamber 48 and decreases the amount of liquid filled in the pump chamber 48, the adverse effect is eliminated by making the total cross-sectional area of the through hole 34 sufficiently large. it can. The chamfer 72 gradually increases the flow passage cross-sectional area from the inner peripheral side of the valve body 40 to the through hole 34, and smoothes the flow of the liquid from the inner peripheral portion of the valve body 40 to the through hole 34.

As shown in FIG. 2, the state of the suction valve 46 during the discharge stroke is such that the liquid guide 44 is compressed in the axial direction by the tightening margin δ due to the clamping force between the valve seat 28 and the valve body 40. , Sitting surface 68
Comes into close contact with the valve seat 28.

In an embodiment of the invention, the liquid guide 44 is
Although it is fixed to the valve element 40, it may be disposed only between the valve seat 28 and the valve element 40 and not particularly connected to the valve element 40. Even if the liquid guide 44 is not connected to the valve element 40, the liquid guide 44 is affected by the collision force of the liquid during the suction stroke and by the moving force of the valve element 40 toward the valve seat 28 during the discharge stroke. , Because it moves integrally with the valve body 40.

In the preferred embodiment of the invention, the liquid guide 44 is made of an elastic material, but the radially inner end of the concave curved surface 66 is axially aligned with, or slightly seated in, the seating surface 68 of the valve body 40. surface
If it is pulled in from 68, the seating surface 68 becomes a contact agent with the valve seat 28 even if it is not elastically compressed, and a rigid material such as metal or resin can be used. Also, the liquid guide 44
Is immersed in liquid even if it is a rigid material,
Predetermined lubricity is ensured.

[Brief description of drawings]

FIG. 1 is a detailed view of the vicinity of a suction valve when the suction valve is opened.

FIG. 2 is a detailed view of the vicinity of the intake valve when the intake valve is closed.

FIG. 3 is a vertical sectional view of a main part of a forced valve triple piston pump.

FIG. 4 is an enlarged view of the vicinity of the liquid guide.

FIG. 5 is a structural diagram of a valve body in a conventional forced valve piston pump.

[Explanation of symbols]

10 Forced Valve Type Triple Piston Pump (Forced Valve Type Piston Pump) 14 Cylinder 22 Piston Rod 28 Valve Seat 32 Stopper with Through Hole (Stopper with Passage) 40 Valve Body 42 Piston Packing 44 Liquid Guide (Intake Fluid Guide Member) 66 Recessed Curved surface (fluid receiving part)

Continuation of the front page (56) Reference JP-A-63-189674 (JP, A) JP-A-61-261680 (JP, A) JP-A-53-2701 (JP, A) Actually-opened 64-64875 (JP , U) Actually open 63-126564 (JP, U) Actually open 61-136183 (JP, U) Actually open 60-114280 (JP, U) Actually open Sho 60-34576 (JP, U) Actually open 49-149304 (JP, U) Actually open 49-28203 (JP, U) Actually open 48-87601 (JP, U) Actually open 3-17183 (JP, U) Actually open 2-103579 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) F04B 21/00-23/14 F16K 15/00-15/20

Claims (4)

(57) [Claims] 1. A stopper (32) with a passage and a valve seat (28) are
The valve body (40) is fixed to the tip of the piston rod (22) at a predetermined interval in relation to the tip end side and the base end side, and the valve body (40) slides the piston packing (42) that slides on the cylinder (14) on the outer peripheral side. Mounted axially on the stopper (32) with the passage and the valve seat (2
8), which is loosely fitted to the piston rod (22) and comes into contact with the stopper with passage (32) and the valve seat (28) during the suction stroke and the discharge stroke, respectively. In the piston pump (10), the suction fluid guide member (44) radiates from the periphery of the end surface of the valve body (40) to the inner surface of the cylinder (14) on the suction side of the valve body (40). The portion on the suction side of the suction fluid guide member (44), which is arranged so as to cover the directional range, protrudes toward the outer side in the radial direction, toward the upstream side, and on the outer side in the radial direction of the valve seat (28) during the suction stroke. A forced valve type piston pump characterized by being a fluid receiving portion (66) with which a fluid passing therethrough collides. 2. The forced valve type piston pump according to claim 1, wherein the suction fluid guide member (44) is made of an elastic material. 3. The suction fluid guide member (44) has a shrinkage margin for ensuring that the valve body (40) is in close contact with the valve seat (28) during a discharge stroke. Forced valve type piston pump described. 4. The suction fluid guide member (44) is the valve body.
The forced valve type piston pump according to any one of claims 1 to 3, wherein the forced valve piston pump is in a disengaged state with (40) and is axially displaceable relative to the piston rod (22). .