JP2844568B2 - Pressure supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure supply device used for supplying a positive pressure for adjusting a boost compensator or supplying a negative pressure for adjusting an aneroid compensator.

[0002]

2. Description of the Related Art As is well known, a boost compensator is a device mounted on a governor of a fuel injection pump for a turbocharged engine, and performs a fuel correction so as to increase a fuel injection amount when a compression pressure is large. It is.
On the other hand, the aneroid compensator is also a device that is installed in the governor, but this device is designed to reduce the fuel injection amount according to the atmospheric pressure when the vehicle travels on high altitudes where the atmospheric pressure is low. This is for performing correction.
The boost compensator and the aneroid compensator may be independent devices, respectively, or may be a fuel correction device having both functions as disclosed in JP-A-2-70930.

In order for the boost compensator or aneroid compensator to exhibit desired performance, it is necessary to apply a predetermined test pressure in advance to adjust each device. That is, in the case of the boost compensator, the adjustment is performed by applying a predetermined positive pressure, while in the case of the aneroid compensator, the adjustment is performed by applying a predetermined negative pressure. Also, in the case of a fuel correction device having both functions of a boost compensator and an aneroid compensator, the above-described positive pressure is applied to the boost compensator mechanism to adjust the mechanism, and then the state where the positive pressure is applied to the boost compensator mechanism is maintained. While applying a negative pressure to the aneroid compensator mechanism, the mechanism is adjusted.

A device that generates the above-mentioned adjusting pressure and supplies the generated pressure to a boost compensator or aneroid compensator is a pressure supply device. FIG. 4 is a schematic configuration diagram of a conventional pressure supply device. The pressure supply device 50 includes a cylinder 51 and a piston 52.
Are separated.

When adjusting the boost compensator B, the boost compensator B and the pressure gauge 55 are connected to the connection port 53a of the positive pressure chamber 53, and the connection port 54 of the negative pressure chamber 54 is connected.
a is closed. On the other hand, when adjusting the aneroid compensator A, the aneroid compensator A and the negative pressure gauge 56 are connected to the connection port 54a of the negative pressure chamber 54, and the positive pressure chamber 53 is adjusted.
Is closed. After the connection, the piston 52 is moved in the direction of arrow X in the figure, so that the positive pressure in the positive pressure chamber 53 increases and the negative pressure in the negative pressure chamber 54 increases. The predetermined adjustment pressure can be set while checking the pressure.

[0006]

In the above-mentioned conventional pressure supply device, the positive pressure value of the positive pressure chamber 53 and the negative pressure value of the negative pressure chamber 54 have a one-to-one relationship, and both pressure values are equal to the piston pressure. 52
Is determined by the position of Therefore, when the boost compensator B and the aneroid compensator A are independently adjusted, there is no problem even with the conventional pressure supply device.

However, when adjusting a fuel compensator having both functions of the boost compensator and the aneroid compensator, it is necessary to apply a negative pressure to the aneroid compensator mechanism while applying a positive pressure to the boost compensator mechanism as described above. . Moreover, if the adjustment pressure (positive pressure) of the boost compensator mechanism is determined, the adjustment pressure (negative pressure) of the aneroid compensator mechanism is not uniquely determined, and there is a range of combinations of the positive pressure value and the negative pressure value. Therefore, this type of fuel correction device could not be adjusted with one conventional pressure supply device. In order to adjust this type of fuel correction device using a conventional pressure supply device, one pressure supply device is required for each of the positive pressure and the negative pressure, which is extremely inconvenient and uneconomical.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. It is an object of the present invention to set a positive pressure and a negative pressure to desired values and to set these pressures to separate systems. It is an object of the present invention to provide a pressure supply device capable of supplying the positive pressure supply circuit and negative pressure supply circuit.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object. The gist of the present invention is to adjust a positive pressure or a negative pressure to a desired level and to apply this pressure to a positive pressure supply circuit or A pressure supply device for leading to a negative pressure supply circuit, comprising (a) a positive pressure adjustment mechanism, a positive pressure adjustment circuit connecting a positive pressure source and a positive pressure supply circuit, and (b) a negative pressure adjustment mechanism, A negative pressure adjustment circuit connected to a negative pressure source and a negative pressure supply circuit, (c) a pressure measurement circuit including a pressure gauge capable of measuring both positive pressure and negative pressure, and (d) the positive pressure adjustment circuit And a circuit switching mechanism for selecting one of the negative pressure adjusting circuits to be connected to the pressure measuring circuit and closing the other circuit.

[0010]

A positive pressure of a desired magnitude can be applied to the positive pressure supply circuit by operating the circuit switching mechanism to connect the positive pressure adjusting circuit and the pressure measuring circuit and operating the positive pressure adjusting mechanism. Thereafter, the circuit switching mechanism is operated to close the positive pressure adjustment circuit and connect the negative pressure adjustment circuit and the pressure measurement circuit. Thus, the state in which the positive pressure is applied to the positive pressure supply circuit can be maintained, and a desired amount of negative pressure can be applied to the negative pressure supply circuit by operating the negative pressure adjustment mechanism. . In addition, as an operation procedure, a negative pressure is adjusted first, the negative pressure is applied to a negative pressure supply circuit, then the circuit is switched, and a positive pressure is adjusted while applying a negative pressure to the negative pressure supply circuit. A procedure of applying the positive pressure to the positive pressure supply circuit may be adopted.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic flow diagram of a pressure supply device according to the present invention. The pressure supply device in this embodiment is used for adjusting a fuel correction device having both functions of a boost compensator and an aneroid compensator.

The pressure supply device 1 includes a positive pressure adjusting circuit 2, a negative pressure adjusting circuit 3, a pressure measuring circuit 4, and a three-way switching valve (circuit switching mechanism) 5. The positive pressure adjusting circuit 2 is connected to the positive pressure source 6, the positive pressure supply circuit 7, and the three-way switching valve 5. The positive pressure control circuit 2 includes a positive pressure control valve (positive pressure control mechanism) 8 and a regulator 9, and the pressure of the positive pressure source 6 is adjusted to a desired level by the positive pressure control valve 8 and adjusted. The positive pressure is supplied to the positive pressure supply circuit 7. The positive pressure supply circuit 7 is a circuit for guiding pressure to the boost compensator mechanism B of the fuel adjusting device.

The regulator 9 is set to the maximum boost pressure P _MAX of the boost compensator mechanism B, and thus, even when the positive pressure control valve 8 is fully opened,
The maximum pressure applied to the positive pressure supply circuit 7 can be suppressed to the maximum boost pressure _PMAX, and the situation where more pressure is applied can be avoided. That is, the regulator 9 functions as a safety valve for the boost compensator mechanism B.

The negative pressure control circuit 3 is connected to the negative pressure source 10, the negative pressure supply circuit 11, and the three-way switching valve 5. The negative pressure control circuit 3 has a branch path 12 that communicates with the atmosphere. A negative pressure control valve (negative pressure control mechanism) 13 is provided in the branch path 12. By adjusting the opening of the negative pressure control valve 13, the pressure of the negative pressure source 10 is adjusted to a desired level in the negative pressure control circuit 3, and the adjusted negative pressure is supplied to the negative pressure supply circuit 11. You. The negative pressure supply circuit 11 is a circuit for guiding pressure to the aneroid compensator mechanism A of the fuel control device.

The pressure measuring circuit 4 includes a pressure gauge 14 capable of measuring both positive pressure and negative pressure, and is connected to the three-way switching valve 5. In this embodiment, the measurement range of the pressure gauge 14 is "-760 mmHg" to "+2000 mmHg", but it is a matter of course that the present invention is not limited to this.

As described above, the three-way switching valve 5 is connected to the positive pressure adjusting circuit 2, the negative pressure adjusting circuit 3, and the pressure measuring circuit 4, and the function of the three-way switching valve 5 is as follows. Switching to three states. The positive pressure adjustment circuit 2 and the pressure measurement circuit 4 are connected, and at the same time, the negative pressure adjustment circuit 3 is closed (hereinafter, this connection state is referred to as “positive pressure adjustment position”). The negative pressure adjustment circuit 3 is connected to the pressure measurement circuit 4, and at the same time, the positive pressure adjustment circuit 2 is closed (hereinafter, this connection state is referred to as "negative pressure adjustment position"). All circuits of the positive pressure adjusting circuit 2, the negative pressure adjusting circuit 3, and the pressure adjusting circuit 4 are closed. FIG. 1 shows the above state.

Next, a description will be given of an adjustment procedure of a fuel correction device having both the boost compensator mechanism B and the aneroid compensator mechanism A using the pressure supply device 1. First, the boost compensator mechanism B is adjusted. For that purpose, the three-way switching valve 5 is set to the “positive pressure adjustment position”, and the positive pressure adjustment circuit 2 and the pressure measurement circuit 4 are connected.
The opening of the positive pressure control valve 8 is adjusted while watching the pressure gauge 14 so that the pressure in the positive pressure adjustment circuit 2 and the pressure in the positive pressure supply circuit 7 become a desired adjustment pressure value. As a result, it is possible to apply a desired positive pressure for adjustment to the boost compensator mechanism B.

Next, while maintaining the state in which the positive pressure for adjustment is applied to the positive pressure supply circuit 7, a negative pressure for adjustment is applied to the negative pressure supply circuit 11 to adjust the aneroid compensator mechanism A. To this end, the three-way switching valve 5 is switched to the "negative pressure adjusting position" to close the positive pressure adjusting circuit 2, and at the same time, the negative pressure adjusting circuit 3 and the pressure measuring circuit 4 are connected to each other.
The opening of the negative pressure control valve 13 is adjusted while watching the pressure gauge 14 so that the pressure in the negative pressure supply circuit 11 becomes a desired pressure value for adjustment. Thus, a desired negative pressure for adjustment can be applied to the aneroid compensator mechanism A while a positive pressure for adjustment of a desired magnitude is applied to the boost compensator mechanism B.

In the above embodiment, the boost compensator mechanism is adjusted, and then the aneroid compensator mechanism is adjusted. However, in some cases, the aneroid compensator mechanism is adjusted first, and the adjustment of the boost compensator mechanism is performed later. It is also possible.
Further, even when the boost compensator or the aneroid compensator is an independent device, it is needless to say that the pressure compensator 1 can be individually adjusted using the pressure supply device 1.

FIGS. 2 and 3 show a specific example of the pressure supply device 1. FIG. 2 is a sectional view and FIG. 3 is a rear view.
The pressure supply device 1 has a housing 30 in which a positive pressure adjustment circuit 2, a negative pressure adjustment circuit 3, a pressure measurement circuit 4, a three-way switching valve 5, and a vacuum pump 10 as a negative pressure source are provided. Is incorporated. Pressurized air, which is a utility in the factory, is used as the positive pressure source. Pressurized air is supplied to the pressure supply device 1 by connecting this pressurized air line to the pressurized air supply port 31. I can do it.

The pressure gauge 14 is a display unit 1 for displaying the detected pressure.
4a is exposed from the front surface 30a of the housing 30. The pressure gauge 14 converts a detected pressure into an electric signal and outputs the electric signal.
It can be taken out from.

Reference numerals 34 and 35 denote a positive pressure outlet and a negative pressure outlet, respectively.
, And the negative pressure supply circuit 11 is connected to the negative pressure outlet 35. The operation knob 5 of the three-way switching valve 5
a protrudes outward from the front surface 30a of the housing 30.

The present invention is not limited to the above-described embodiment, and various modes can be adopted. For example, in the above-described embodiment, the circuit switching mechanism is constituted by a three-way switching valve. However, it is also possible to function like a three-way switching valve by combining a plurality of ON-OFF valves. In addition, the mode of use of the pressure supply device is not limited to the adjustment of the boost compensator or the aneroid compensator.

[0024]

As described above, according to the present invention, a positive pressure control circuit, a negative pressure control circuit, a pressure measuring circuit, and a circuit switching mechanism constitute a pressure supply device. There is an excellent effect that these pressures can be set to desired values and these pressures can be respectively supplied to the separate positive pressure supply circuit and negative pressure supply circuit.

[Brief description of the drawings]

FIG. 1 is a schematic flow diagram of a pressure supply device according to the present invention.

FIG. 2 is a sectional view of a specific example of the pressure supply device according to the present invention.

FIG. 3 is a rear view of a specific example of the pressure supply device according to the present invention.

FIG. 4 is a schematic flow diagram of a conventional pressure supply device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pressure supply device 2 positive pressure adjustment circuit 3 negative pressure adjustment circuit 4 pressure measurement circuit 5 three-way switching valve (circuit switching mechanism) 6 positive pressure source 7 positive pressure supply circuit 8 positive pressure adjustment valve (positive pressure adjustment mechanism) 10 negative pressure Source 11 Negative pressure supply circuit 13 Negative pressure control valve (negative pressure control mechanism) 14 Pressure gauge

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-255226 (JP, A) JP-A-2-70930 (JP, A) JP-A-59-91432 (JP, U) JP-A-3-97 25828 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) F02M 65/00 305 F02D 1/02 321

Claims (1)

(57) [Claims] 1. A pressure supply device for adjusting a positive pressure or a negative pressure to a desired magnitude and guiding the pressure to a positive pressure supply circuit or a negative pressure supply circuit, comprising: (a) a positive pressure adjustment mechanism, A positive pressure control circuit connecting the positive pressure source and the positive pressure supply circuit; (b) a negative pressure control circuit including a negative pressure control mechanism and connecting the negative pressure source and the negative pressure supply circuit; A pressure measuring circuit equipped with a pressure gauge capable of measuring both pressures, and (d) selecting one of the positive pressure adjusting circuit and the negative pressure adjusting circuit and connecting the selected circuit to the pressure measuring circuit, A circuit switching mechanism that closes the other circuit,
A pressure supply device comprising: