JP2001248563A - Pulsation type diaphragm pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulsation type diaphragm pump capable of reducing assembling man-hours with reduced number of parts without impairing the reliability for a pump function. SOLUTION: Valve seat bodies 22, 27 of a suction valve 21 and discharge valve 26 are protruded inside a pump chamber 6 and a discharge chamber 14, respectively, and vale elements 25, 30 opening and closing valve seat ports 23, by coming into contact with their seat faces 24, 28 and leaving from them are formed in parts facing the valve seat bodies 22, 27 of a pump diaphragm 3 and a pastor diaphragm 10. Two diaphragms 3, 10 reciprocating and displacing by pressure pulsation serve also as the valve elements 25, 30 of the suction valve 21 and the discharge valve 26, thereby reducing the number of parts and assembling man-hours and providing the required pump function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulsating diaphragm which is driven by pressure pulsation generated in a crankcase or an intake manifold with the operation of an engine and is used for supplying fuel mainly to a two-cycle gasoline engine. It relates to a pump.

[0002]

2. Description of the Related Art A pulsating diaphragm pump is a mechanical or electromagnetic pump as a means for supplying fuel to a two-cycle or four-cycle small gasoline engine which is a power source of an agricultural machine, an outboard motor, a light vehicle, or the like. It is widely used because it has an advantage that it has a simpler structure and can be driven without mechanical loss as compared with that of the above.

FIG. 4 is a cross-sectional view showing an example of a conventional general pulsating diaphragm pump. A pump diaphragm 52 and a cover 53 are overlapped on one surface of a main body 51 and provided on the main body 51. Pump diaphragm 5
The recess covered by 2 forms a pump chamber 54, and the inside of the cover body 53 forms a pulse chamber 55, in which a diaphragm spring 57 is housed.

A pulsator diaphragm 58 and a cap 59 are overlapped on another surface of the main body 51. Two dents provided in the main body 51 and covered by the pulsator diaphragm 58 define a suction chamber 60 and a discharge chamber 62. The interior of the cap 59 is formed in the air chamber 6 communicating with the atmosphere.
4 are formed. Further, a suction valve 65 is provided between the suction chamber 60 and the pump chamber 54, and a discharge valve 67 is provided between the pump chamber 54 and the discharge chamber 62.

A pressure pulsation of air generated in the crankcase or the intake manifold with the operation of the engine, generally a pressure pulsation generated in the crankcase, is transmitted from a pulse inlet 56 provided in the cover 53 to a pulse chamber 55. After being introduced, the pump diaphragm 52 is reciprocally displaced, and fuel in a fuel tank (not shown) is supplied from the fuel inlet 61 to the suction chamber 60,
The fuel is sent to the fuel outlet 63 via the suction valve 65, the pump chamber 54, the discharge valve 67, and the discharge chamber 62, and supplied to the engine from a carburetor (not shown). In the suction chamber 60 and the discharge chamber 62, the pulsation of the fuel is smoothed by the pulsator diaphragm 58, so that the suction efficiency and the discharge efficiency are improved.

[0006]

The suction valve 65 and the discharge valve 67 are check valves mounted on the bottom wall of the main body 51 which divides the pump chamber 54, the suction chamber 60 and the discharge chamber 62. The valve bodies 66 and 68 for opening and closing the valve seats that communicate the pump chamber 54 with the pump chamber 54 and the valve seats that communicate the pump chamber 54 and the discharge chamber 62 are the minimum necessary parts, so that the valve can be reliably closed. In order to achieve this, a check valve configured using components such as a valve-closing spring acting on a valve body and a spring receiver for pressing the valve-closing spring is often used.

[0007] For this reason, it is difficult to meet the demand for purchasing a pump having a reliable pump function at low cost because the number of pump components is large and the number of assembling steps is large.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and has a reduced number of parts, a reduced number of assembling steps, an inexpensive provision, and a reliable pump function. It is an object of the present invention to obtain a pulsating diaphragm pump which does not impair the performance.

[0009]

SUMMARY OF THE INVENTION The present invention provides a fuel suction chamber and a discharge chamber, a pump chamber, and a pump diaphragm that reciprocates and changes the volume of the pump chamber due to pressure pulsation generated during operation of the engine. A pulsator diaphragm for smoothing the pulsation of fuel generated in the suction chamber and the discharge chamber;
2. Description of the Related Art A pulsating diaphragm pump having a suction valve that communicates and shuts off a suction chamber and a pump chamber and a discharge valve that communicates and shuts off a pump chamber and a discharge chamber is provided, especially because of a suction valve and a discharge valve. The above-mentioned problem has been solved as follows.

That is, with respect to the suction valve, the valve seat is projected into the interior of the pump chamber, and the valve body that opens and closes the valve seat by contacting / separating from the seat surface, which is the end surface, is provided on the valve seat of the pump diaphragm. It was a facing part. For the discharge valve, the valve body protrudes into the discharge chamber, and the valve body that opens / closes the valve seat by contacting / separating from the seat surface, which is the end surface, faces the valve seat body of the pulsator diaphragm. And

The pump diaphragm separates from the seat surface in a suction stroke that is displaced in a direction to increase the volume of the pump chamber, but is in contact with the seat surface in a discharge stroke that is displaced in a direction to reduce the volume of the pump chamber. On the other hand, the pulsator diaphragm comes into contact with the seat surface during the suction stroke, but separates from the seat surface during the discharge stroke. In this manner, the two reciprocatingly displaced diaphragms themselves function as the respective valve elements of the suction valve and the discharge valve, so that the fuel suction and discharge of the pump chamber can be appropriately performed.

By using the pump diaphragm and the pulsator diaphragm which are conventionally provided as the functional parts for the valve body, the number of parts is small, so that the number of assembling steps can be reduced and the cost can be reduced. In addition, the object of obtaining a reliable pulsating diaphragm pump without impairing the functions of the suction valve and the discharge valve as check valves is achieved.

In order to completely seat the valve body in contact with the seat surface when the suction valve and the discharge valve are closed,
As for the suction valve, it is preferable that the diaphragm retainer of the pump diaphragm is eccentrically provided at a position not overlapping the seat surface, or that the pump diaphragm is formed in a flat surface shape so as to contact the seat surface in a flat surface state. In addition, for one or both of the suction valve and the discharge valve, the seat surface of the valve seat body is formed by an elastic sealing member, or the valve body portion of the diaphragm is formed to have a thick wall protruding toward the seat surface. ,
Alternatively, it is preferable that the base fabric of the diaphragm is biased toward the surface opposite to the sheet surface.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. 1. A pump diaphragm 3 and a cover body 5 are superposed on one surface of a main body 1 and provided on the main body 1. The cavity covered by the pump diaphragm 3 forms a pump chamber 6. The cover body 5 has a pulse introduction port 7 connected to the crankcase of the engine or to the intake manifold. The inside thereof forms a pulse chamber 8 in which a diaphragm spring 9 is housed.

A pulsator diaphragm 10 and a cap 11 are overlapped on another surface parallel to the above-mentioned surface of the main body 1. Two depressions provided in the main body 1 and covered by the pulsator diaphragm 10 are provided in the suction chamber 12. And a discharge chamber 14, wherein the suction chamber 12 has a fuel inlet 13 connected to a fuel tank, and the discharge chamber 14 has a fuel outlet 15 connected to a carburetor. Cap 1
1 forms an air chamber 16 communicating with the atmosphere.

The pump chamber 6 and the suction chambers 12, which are open to two surfaces of the main body 1 and have recesses provided back to back, are formed.
A cylindrical valve seat 22 is provided in the portion of the suction chamber 12 of the bottom wall 2 that partitions the discharge chamber 14 into the interior of the pump chamber 6. The pump chamber 6 has a valve seat port 23 serving as a passage communicating with the pump chamber 6, and a front end surface on the pump chamber 6 side is a seat surface 24.
This seat surface 24 is a pump diaphragm 3 that reciprocates.
Is located close to the pump diaphragm 3 so as to contact at an appropriate position in the middle of the displacement stroke. The portion of the pump diaphragm 3 facing the seat surface 24 functions as a valve body 25 for opening and closing the valve seat 23. The aforementioned valve seat 2
2, the valve seat 23, the seat surface 24, and the valve body 25 constitute the suction valve 21.

On the other hand, a cylindrical valve seat 27 is provided in the discharge chamber 14 on the bottom wall 2 so as to protrude into the discharge chamber 14. The valve seat 27 is connected to the pump chamber 6 and the discharge chamber 14. Room 14
And a valve seat port 28 which is a passage for communicating with the discharge chamber 14. The seat surface 29 is located at a position where the pulsator diaphragm 10 comes into contact with an inoperative position when the engine is stopped or at an appropriate position in the middle of a reciprocating displacement stroke. A portion of the pulsator diaphragm 10 facing the seat surface 29 is a valve seat opening 28. Acts as a valve element 30 that opens and closes. The valve seat 27, the valve seat 28, the seat surface 29 and the valve 30 constitute a discharge valve 26.

The diaphragm retainer 4 which is superimposed on the pump diaphragm 3 and receives the diaphragm spring 9 may be concentric with the pump diaphragm 3 as in the conventional product. However, in the embodiment shown in FIG. 1, the diaphragm retainer 4 is not used. When the suction valve 21 is closed, the diaphragm retainer 4 does not overlap with the seat surface 24, and only the flexible pump diaphragm 3 overlaps with the seat surface 24 so that the valve can be completely closed. I did it. In this manner, the pump diaphragm 3 uses the portion of the diaphragm spring 9 that is not limited by the generally minute stroke of the diaphragm spring 9 as the valve body 25 as the seat surface 24.
, The suction valve 21 can be greatly opened to increase the fuel flow rate.

In this embodiment having such a configuration, when pressure pulsation generated in the crankcase during operation of the engine is introduced into the pulse chamber 8 from the pulse introduction port 7, the engine piston moves to the top dead center. As a result, the pump diaphragm 3 is displaced toward the pulse chamber 8 by the negative pressure generated thereby to generate a negative pressure in the pump chamber 6 and the valve body 2.
5 leaves the sheet surface 24. As a result, the fuel in the suction chamber 12 flows into the pump chamber 6, while the pulsator diaphragm 10 is sucked by the negative pressure of the pump chamber 6 and comes into close contact with the seat surface 29 to close the discharge valve 26.

When the pump diaphragm 3 is displaced toward the pump chamber 6 by the positive pressure generated when the engine piston moves to the bottom dead center, the fuel in the pump chamber 6 is pressurized and the pulsator diaphragm 10 is moved to the air chamber 16. And the valve body 30 is separated from the seat surface 29 to send the fuel in the pump chamber 6 from the discharge chamber 14 to the fuel outlet 15. On the other hand, the valve body 25 of the pump diaphragm 3 is in close contact with the seat surface 24 to close the suction valve 21.

By repeating the above, the fuel is supplied to the suction chamber 12.
Is sent to the discharge chamber 14 via the pump chamber 6, and the suction valve 21 and the discharge valve 26 form the valve bodies 25 and 30 by the pump diaphragm 3 and the pulsator diaphragm 10, which are functional parts of the pump. A large fuel flow can be easily obtained by the stroke of the two diaphragms 3 and 10, especially the valve bodies 25 and 30 and the position of the seat surfaces 24 and 29, by not using a dedicated valve element which operates independently. Can be.

Next, FIG. 2A shows a pump diaphragm 3.
The peripheral part sandwiched between the main body 1 and the cover body 5 and the effective diameter portion which reciprocates are formed into a flat surface shape which is located on the same plane at the inoperative position when the engine is stopped.
Are in contact with the sheet surface 24.
The flat surface shape is the same as that of the pulsator diaphragm 10, and completes closing of the suction valve 21 during the discharge stroke.

FIG. 2 (B) shows a sealing member 3 made of an O-ring at the tip of the valve seats 22 and 27 in order to complete the closing of the suction valve 21 and the discharge valve 26.
2, the seat surfaces 24, 29 where the valve bodies 25, 30 come into contact with / separate from each other are formed by this elastic sealing member 32, and the valve bodies 25,
The elastic members 30 are in elastic contact with each other with respect to the sealing member 32, thereby creating a completely close valve closing state.

FIG. 2C also shows an embodiment in which the suction valve 21 and the discharge valve 26 are completely closed. This is the seat surface 2 at the tip of the valve seat body 22, 27.
The valve bodies 25 and 30 facing the first and second diaphragms 4 and 29 are formed by forming these portions of the diaphragms 3 and 10 to have a thick wall bulging toward the seat surfaces 24 and 29, respectively. The elastic force of the rubber is strengthened at the valve bodies 25 and 30 to create a valve-closed state that is completely in contact with the seat surfaces 24 and 29.

FIG. 2D shows another embodiment for completely closing the suction valve 21 and the discharge valve 26. In this embodiment, the base fabric 34 embedded in the diaphragms 3 and 10 is embedded such that the base fabric 34 is offset toward the surface opposite to the sheet surfaces 24 and 29.
By making full use of the elastic force of the rubber, which is the material described above, the portions of the valve bodies 25 and 30 are brought into contact with the seat surfaces 24 and 29 to complete the valve closing state.

The embodiment shown in FIGS. 2B, 2C and 2D is not necessarily applied to both the suction valve 21 and the discharge valve 26, but is applied to only one of them. Alternatively, different embodiments can be appropriately selected and applied to the suction valve 21 and the discharge valve 26. For example, applying the one shown in FIGS. 2B, 2C, and 2D to the discharge valve 26 in the embodiment shown in FIG. 1 is an example.

FIG. 3 shows six pulsating diaphragm pumps manufactured and sold in Japan and overseas having the same capacity.
1 shows the results of a comparison test of the fuel flow rate with the embodiment shown in FIG. 1 made to have the same capacity, and shows the results of conventional products No. 1, No. 2, No. 3, No. 4, No. .5, No.6
In comparison with the present invention, it was found that a large fuel flow rate was obtained according to the present invention.

[0028]

As described above, according to the present invention, the valve elements of the suction valve and the discharge valve are formed by the pump diaphragm and the pulsator diaphragm which are functional parts of the pump itself, so that the number of parts is small, and the number of assembling steps is reduced. A reliable pump equipped with a suction valve and discharge valve that can be provided at reduced cost and that opens and closes using the reciprocating displacement of each diaphragm without losing the function as a check valve. Is obtained. Further, a large fuel flow rate can be easily obtained as compared with the conventional one.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIGS. 2A, 2B, 2C, and 2D are partial longitudinal sectional views showing different embodiments of the present invention.

FIG. 3 is a performance comparison diagram of a product of the present invention and a conventional product.

FIG. 4 is a longitudinal sectional view showing a conventional example.

[Explanation of symbols]

3 pump diaphragm, 4 diaphragm retainer,
6 pump chamber, 9 diaphragm spring, 10 pulsator diaphragm, 12 suction chamber, 14 discharge chamber, 2
1 suction valve, 22, 27 valve seat, 23, 28 valve seat, 24, 29 seat surface, 25, 30 valve, 26 discharge valve, 32 seal member,

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F04B 11/00 F16K 15/14 C 3H077 53/10 7/17 B F16K 15/14 31/126 Z // F16K 7/17 F04B 9/12 H 31/126 21/02 GF term (reference) 3G066 AA01 AA08 AB02 BA12 BA56 BA61 CA01T CA04T CA07 CA22T CA39T CD17 CE13 CE14 3H056 AA07 BB32 BB33 CA08 CB03 CC20 CD10 GG18 ABB18BB22 CA12 CA23 CC01 DD19 EE01 EE15 3H071 AA07 BB01 CC17 CC25 CC31 CC32 CC34 DD03 DD04 DD12 DD13 DD14 3H075 AA03 BB04 BB14 CC03 CC30 CC32 CC33 CC35 DA05 DA09 DA16 DA17 DB10 3H077 AA03 BB01 CC02 DD03 EE04 FF03 FF04 FF04

Claims (6)

[Claims] 1. A pump diaphragm for changing the volume of the pump chamber by reciprocating displacement by a pressure pulsation generated by operation of an engine, a suction chamber and a discharge chamber of the fuel, a pump chamber, and the pump chamber. A pulsator diaphragm having a pulsator diaphragm for smoothing the pulsation of fuel generated in the pump, a suction valve for communicating and shutting off the suction chamber and the pump chamber, and a discharge valve for communicating and shutting off the pump chamber and the discharge chamber. In the pump, the suction valve protrudes a valve seat body into the pump chamber and contacts / separates a seat surface which is an end surface thereof to open and close a valve seat opening. The discharge valve has a valve seat protruding into the discharge chamber and contacts / separates a seat surface which is an end surface thereof. And it is intended to the valve body for opening and closing the valve seat port formed in the valve seat body on opposite portions of said pulsator diaphragm, pulsatile diaphragm pump, characterized in that. 2. The pulsating diaphragm pump according to claim 1, wherein a diaphragm retainer of the pump diaphragm is eccentrically provided at a position not overlapping with a seat surface of the suction valve. 3. The pulsating diaphragm pump according to claim 1, wherein the pump diaphragm is formed in a flat surface shape so that the pump diaphragm comes into contact with a seat surface of the suction valve in a flat surface state. 4. The valve seat according to claim 1, wherein at least one of the suction valve and the discharge valve is provided with an elastic seat member, and a seat surface with which the valve body contacts and separates is formed by the seal member. Item 2. A pulsating diaphragm pump according to item 1. 5. A pulsating diaphragm pump according to claim 1, wherein at least one of said pump diaphragm and said pulsator diaphragm has a valve body portion formed to have a large thickness rising toward said seat surface. 6. The pulsating diaphragm pump according to claim 1, wherein at least one base fabric of said pump diaphragm and said pulsator diaphragm is biased to a surface opposite to said sheet surface.