JPS595193Y2 - Diaphragm pump - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a diaphragm pump that can be used simultaneously and suitably on the suction side as a negative pressure source and on the discharge side as a positive pressure source.

BACKGROUND ART Conventionally, for example, a brake booster is known which is able to obtain a strong braking force even if it is small by introducing negative pressure and positive pressure to the front and rear of a power piston.

The pressure sources for this brake booster are generally an engine intake negative pressure as a negative pressure source and an air pump as a positive pressure source, but in recent years, various types of devices that use negative pressure as an operating source have been installed in vehicles. In addition, as it became impossible to obtain large negative pressure due to exhaust gas countermeasures, diaphragm pumps were added as negative pressure sources.

As a result, conventionally, two pumps are required, resulting in high cost.

By the way, it is possible to use the suction side of one pump as a negative pressure source and the discharge side as a positive pressure source, but in general, including the brake booster mentioned above, the values of the necessary negative pressure and positive pressure are In many cases, it is difficult to use one pump as a negative pressure source and a positive pressure source at the same time.

In view of these points, the present invention forms a passage in the casing of the diaphragm pump that communicates each of the intake port and the discharge port with the atmosphere. Provided is a diaphragm pump in which suction side pressure, that is, negative pressure, and discharge side pressure, that is, positive pressure, can be set to predetermined different pressures by providing valve mechanisms that open when respective set values are exceeded. It is something to do.

The present invention will be described below with reference to the illustrated embodiment. In FIG. 1, 1 is a casing consisting of an upper body 2 and a lower body 3, and the outer circumference of a diaphragm 4 is held between the upper body 2 and the lower body 3. There is.

An operating rod 5 is supported by the lower body 3 so as to be able to reciprocate up and down, and its upper end is connected to the diaphragm 4 by a screw 7 passing through the diaphragm 4 and a plate 6 provided on the upper and lower surfaces thereof. Further, the lower end portion is connected to one end of a connecting rod 9 via a pin 8.

The other end of this connecting rod 9 is connected to an eccentric shaft portion 10a of a drive shaft 10 that is pivotally supported on the lower body 3, and a gear 11 that is linked to a drive source such as an engine (not shown) is attached to this drive shaft 10. It is being

12 is a working chamber formed by the diaphragm 4 and the recessed part of the upper body 2; 13 and 14 are an intake port and a discharge port that communicate with the working chamber, respectively; inside the intake port 13 is an intake valve 15; A discharge valve 16 is disposed within each of the discharge valves 14 .

The intake valve 15 has a function of allowing fluid to flow from the outside to the working chamber 12, and the discharge valve 16 has a function of allowing fluid to flow from the working chamber 12 to the outside.

In addition, 17.18 is the above-mentioned intake port 13 and discharge port 1.
This is a connecting pipe provided between 4 and 4.

Such a configuration is basically the same as that of a conventionally known diaphragm pump, and when the drive shaft 10 is rotationally driven by a drive source (not shown) via the gear 11, the eccentric shaft portion 10a is interlocked with the drive shaft 10. The operating rod 5 is reciprocated via the connecting rod 9, and therefore the diaphragm 4 is displaced up and down, so that the volume within the operating chamber 12 is increased or decreased.

When the volume inside the working chamber 12 increases, the intake valve 15
The external fluid is sucked into the working chamber 12 through the working chamber 1.
When the volume within the working chamber 12 decreases, the fluid within the working chamber 12 is discharged to the outside via the discharge valve 16.

However, in the present invention, a passage 19 communicating the intake port 13 with the atmosphere and a passage 20 communicating the discharge port 14 with the atmosphere are provided in the upper body 2 at positions outside the intake valve 15 and the discharge valve 16, respectively. Each bow in each passage 19.20) 13.14
A valve mechanism 21,22 is provided which opens when the pressure difference between the internal pressure and the atmospheric pressure exceeds a set value.

That is, the valve mechanism 21 on the side of the intake port 13 is composed of a valve body 23 and a spring 24. Normally, the valve body 23 closes the passage 19 by the elastic force of the spring 24. When the pressure increases and exceeds a predetermined value, the pressure difference between the atmosphere and the negative pressure causes the valve body 23 to open.
A24 is opened to maintain the negative pressure inside the intake port 13 below the predetermined value.

On the other hand, the valve mechanism 22 also includes a valve body 25 and a spring 26, and the valve body 25 normally closes the passage 20, but when the positive pressure inside the discharge port 14 increases and exceeds a predetermined value, The valve body 25 is opened to release the pressure in the discharge port 14 to the atmosphere, and the positive pressure in the discharge port 14 is maintained below a predetermined value.

Therefore, in the present invention, by selecting the set loads of the springs 24 and 26 separately, the maximum value of the negative pressure in the intake port 13 and the maximum value of the positive pressure in the discharge port 14 can be independently set. It becomes possible to set.

Next, Fig. 2 shows an example of the use of the diaphragm pump P having the above structure. In the intake pipe, the negative pressure side of the brake booster 27 and the intake pipe 28 are communicated through a conduit 30 via a check valve 29 .

The suction side of the diaphragm pump P is connected to a conduit 30 on the side of the brake booster 27 from the check valve 29 via a conduit 31 connected to the connecting pipe 17, and the discharge side is connected to the connecting pipe 18. It is connected to the positive pressure side of the brake booster 27 via a conduit 32 .

Therefore, when the engine is started and the pump P is activated, negative pressure and positive pressure are introduced into the brake booster 27, and at the same time, the negative pressure generated in the intake pipe 28 is also introduced.

At this time, as described above, the valve mechanism 21 is connected to the pump P.
．． 22, the positive pressure and negative pressure introduced into the brake booster 27 can be controlled separately.

Furthermore, FIG. 3 shows another example of the use of the diaphragm pump P, in which 33 is a brake booster whose operating source is the pressure difference between negative pressure and atmospheric pressure, 34 is an engine intake pipe, and 35 is a This is a reburning device for purifying exhaust gas, and the negative pressure side of a brake booster 33 and an intake pipe 34 are communicated through a conduit 37 via a check valve 36.

The suction side of the diaphragm pump P is connected to a conduit 37 on the side of the brake booster 33 from the check valve 36 via a conduit 38 connected to the connection pipe 17, and the discharge side is connected to the connection pipe 18. It is connected via a conduit 39 to a reburning device 35 .

Therefore, even in this case, by starting the engine, negative pressure can be introduced into the brake booster 33, air for recombustion can be supplied to the afterburner 35, and negative pressure can be introduced into the brake booster 33. and reburner 35
The air pressure supplied to each can be controlled separately.

In the above embodiment, an adjusting means may be provided so that the set loads of the springs 24, 26 that bias the valve bodies 23, 25 can be adjusted freely from the outside.

As described above, the present invention allows each of the intake port and the discharge port to communicate with the atmosphere through the passage formed in the diaphragm casing, and each of these passages has a
Since each valve mechanism is equipped with a valve mechanism that opens when the difference between the internal pressure of each port and the atmospheric pressure exceeds a separately set value, the maximum values of intake pressure and discharge pressure can be set separately. Therefore, one diaphragm pump can be used under suitable conditions as a negative pressure source and a positive pressure source for a device that requires different negative pressures and positive pressures.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention, and FIGS. 2 and 3 are piping system diagrams shown in FIG. 1 and showing an example of use of the diaphragm pump. 1...Casing, 4...Diaphragm, 13...Intake port, 14...Discharge port), 19.20...Passage, 21゜22・
...Valve mechanism.

Claims (1)

[Scope of utility model registration request] In a diaphragm pump that sucks in fluid from an intake port and discharges fluid from a discharge port by displacement of a diaphragm, each of the intake port and the discharge port is communicated with the atmosphere through a passage formed in the diaphragm casing, and each of these passages is provided. The diaphragm pump is characterized in that it is provided with a valve mechanism that opens when the pressure difference between the internal pressure of each port and the atmospheric pressure exceeds a set value set for each port.