JPH0533777A - Pressure fluid generating device - Google Patents

Abstract

PURPOSE:To provide a pressure fluid generating device of which flow pressure characteristic is excellent, heating of fluid is small, a piping quantity is small and power is saved. CONSTITUTION:In a pressure fluid generating device to forcedly feed fluid 12 with a pump 14 and supply it from an outlet, pressure of the fluid in the vicinity of the outlet is detected by a pressure sensor 18, and the rotating speed of the pump is controlled by a control circuit 15 based on the output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure fluid generator used in an electronic fuel injection device for an automobile engine or the like.

[0002]

2. Description of the Related Art FIG. 4 is a schematic view showing a conventional example of a mechanical pressure fluid generator. In the fluid reservoir 41,
The container 42 is filled with a fluid 42 such as fuel and
3 is in communication with the pump 44. Pump 44
Is driven by the electric power from the power supply 45 and supplies the fluid 42 to the outlet OUT through the conduit 46. In the pipe line 46,
A pressure gauge 47 is provided and constantly displays the pressure of the supplied fluid. In addition, a conduit 48 branched from the conduit 46
Is provided with a relief valve 49 that discharges the fluid 41 when a predetermined pressure value is reached.
It is returned to the container 41 via 8. Therefore, the pressure in the conduit 46 and the outlet OUT becomes the pressure set by the relief valve 49.

[0003]

However, in the above-mentioned conventional pressure fluid generator, the amount flowing through the relief valve 49 changes depending on the amount discharged from the outlet OUT through the flow path 46. The relief valve 49 has a characteristic that even if the set pressure is constant, the pressure increases when the relief flow rate is large, and the pressure decreases when the relief flow rate is small. That is, since the flow valve-pressure characteristic of the relief valve 49 is poor, it is difficult to maintain the fluid pressure discharged from the flow path 46 at a predetermined pressure regardless of the flow rate.

Further, since the pump 44 constantly sends a fixed amount, the fluid 42 is circulated through the pipe line 48. Therefore, there is a problem that the temperature of the fluid 42 rises due to heat generation of the pump 44 and the like.

Furthermore, the relief system has a problem that the pipe 48 for the return is required and the piping is complicated, so that it is necessary to look at the pressure gauge to change the pressure.

Moreover, since the pump 44 has to be constantly rotating, there is a problem that the power consumption is large and the life of the pump 44 and the like is short.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, to provide a pressure fluid generator having good flow-pressure characteristics, small heating of fluid, a small amount of piping, and power saving. ..

[0008]

In order to solve the above-mentioned problems, a pressure fluid generator according to the present invention is a pressure fluid generator in which a fluid is pumped by a pump and supplied from an outlet,
It is composed of a pressure sensor that detects the pressure of the fluid near the outlet, and a control circuit that controls the rotation speed of the pump based on the output of the pressure sensor.

[0009]

According to the present invention, the pressure of the fluid is detected by the pressure sensor and the pressure servo is applied to the pump for pressurizing the fluid.

[0010]

The present invention will be described in detail below with reference to the drawings and the like. FIG. 1 is a schematic view showing an embodiment of a pressure fluid generation device according to the present invention, FIG. 2 is a view showing a fluid pressurizing pump of the pressure fluid generation device according to the embodiment, and FIG. 3 is a pressure according to the present invention. It is the diagram which showed the flow rate pressure characteristic of the fluid generator compared with the prior art example.

In FIG. 1, 11 is a fluid reservoir, and 12
Is a fluid, 13 and 16 are conduits, and 17 is a pressure gauge, and the same ones as in the above-mentioned conventional example can be used.

The pressure sensor 18 is provided in the conduit 16, detects the pressure near the outlet of the fluid 12, and its output is connected to the servo circuit 15.

The servo circuit 15 is a control circuit for following the output of the pressure sensor 18 and changing the rotational speed of the pump 14.

The pump 14 is arranged between the conduits 13 and 16, and as shown in FIG. 2, the rotor 22 is eccentrically provided in the spacer 21. When the rotor 22 rotates, the plurality of rollers 2 provided on the outer periphery of the rotor 21
3 is pushed outward and rotates while pressing against the inner wall of the pump spacer 21. Since the spacer 21 and the rotor 22 are eccentric, a pump action works due to a change in the gap between the inner wall of the spacer 21 and the outer periphery of the rotor 22, and the fluid is pumped from the suction port to the discharge port. This pump 14
It has the advantages of low starting torque, good durability, and low pulsation.

A damper 19 is provided in the pipe line 16 to eliminate the pulsation of the pump 14 and stabilize the pressure.

Next, the operation of the embodiment of the pressure fluid generator according to the present invention will be described. When a start switch (not shown) is turned on, the pump 14 rotates, and the fluid 12 in the fluid reservoir 11 is discharged from the outlet OUT via the conduits 13 and 16. At this time, the pressure sensor 18 detects the pressure in the conduit 16, and when the output changes, the servo circuit 15 variably controls the rotation speed of the pump 14 so as to correct the change.

FIG. 3 shows the measurement results of the flow-pressure characteristics of this embodiment and the above-mentioned conventional example. In this, the flow rate discharged from the outlet OUT is taken on the X axis and the pressure at the outlet OUT is taken on the Y axis. In both the embodiment and the conventional example, the pressure when the flow rate is zero is set to be equal. It is apparent that the pressure drop with the increase of the flow rate is extremely small in the embodiment as compared with the conventional example. As described above, the flow rate-pressure characteristic is extremely good in the embodiment because it is electrically controlled as compared with the conventional mechanical relief type.

In the above embodiment, the fluid 12 was taken out from the fluid reservoir 11, but in another embodiment, the pressure fluid of the present invention is generated in the fluid taken out by branching a pipe from a fluid line such as a pipe. A device can be employed. However, if the pressure on the fluid line side is P1 and the pressure after passing through the pressure fluid generation device is P2, then P2> P1.

[0019]

As described in detail above, according to the present invention, even if the flow rate is increased, the pressure at the outlet does not decrease, pulsation is small, and pressure setting is easy. Further, since it is not necessary to circulate the fluid, the temperature of the fluid does not rise, and a return conduit or the like is unnecessary. In addition, it consumes less power and the life of pumps is extended.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a pressure fluid generation device according to the present invention.

FIG. 2 is a diagram showing a fluid pressurizing pump of the pressure fluid generation device according to the embodiment.

FIG. 3 is a diagram showing flow rate pressure characteristics of a pressure fluid generation device according to the present invention in comparison with a conventional example.

FIG. 4 is a schematic diagram showing a conventional example of a mechanical pressure fluid generation device.

[Explanation of symbols]

 11 Fluid Reservoir Container 12 Fluid 13, 16 Pipeline 14 Pump 15 Servo Circuit 17 Pressure Gauge 18 Pressure Sensor 19 Damper

Claims (1)

Claim: What is claimed is: 1. A pressure fluid generator for pumping a fluid by a pump to supply the fluid from an outlet, the pressure sensor detecting a pressure of the fluid near the outlet, and an output of the pressure sensor. And a control circuit for controlling the rotation speed of the pump.