JPS624687Y2 - - Google Patents

Description

[Detailed description of the invention] This invention was developed to determine the leak status of fuel injection valves used in diesel engines of ships, etc., for the purpose of determining the operation quality of the valve mechanism and acquiring data for adjustment.
The present invention relates to a test device suitable for testing ventilation function, valve opening pressure, spray condition, etc.

Figure 1 shows a fuel injection valve used in a B&W-GF type diesel engine. In the drawing, 1 is a valve body case, which is fixed to a base plate 2 and has a nozzle body 3 protruding from it. It has an opening at the tip for attachment. 4 is a cylindrical valve body, 6 is a cylindrical high-pressure valve body, 7 is a cylindrical low-pressure valve body, 8
9 is an intermediate member, 9 is a sleeve, and 10 is a rod-shaped member, which are incorporated into the valve body case 1 in the axial direction. The high-pressure valve body 6 has a valve part 61 at its tip that engages with the hole 4' of the valve body 4, and a plurality of small holes 62 that open on the circumferential surface near the valve part 61. It is constantly pressed in the distal direction within the valve body 4 by a high-pressure spring 12 via a spring receiver 11 . The low-pressure valve body 7 is fitted into the high-pressure valve body 6, and has a tip portion 71 that comes into contact with the valve seat 63 of the high-pressure valve body 6 at the tip.
The distal end portion 71 has a plurality of small holes 72 that open on the circumferential surface near the distal end portion 71, and a low pressure spring 13 disposed between the intermediate member 8 and the high pressure valve body 6 constantly operates in the distal direction. are being oppressed. A small diameter portion 81 at the tip of the intermediate member 8 is fitted into the upper end of the low pressure valve body 7, and an orifice 82 formed in the small diameter portion 81 normally opens into a low pressure spring chamber 83. Fuel passages 6a, 7a, 8a, and 10a are provided in the high-pressure valve body 6, the low-pressure valve body 7, the intermediate member 8, and the rod-shaped members 10, 10,
Among the above fuel passages, fuel passages 7a, 8a, 10a
is in constant communication. 14 is an orifice-shaped air vent hole.

In the fuel injection valve having the above structure, the fuel passage 10
When the fuel is sent from a and the passages 7a, 8a, and 10a are filled with fuel, the fuel enters each part of the valve from the orifice 82, and the residual air in each part of the valve is released from the air vent hole 14, and finally, the fuel enters each part of the valve. is also filled with fuel oil. By the way, since the amount of fuel supplied from the fuel passage 7a is much larger than the amount flowing out from the orifice 82, the fuel pressure in the passage increases.
This fuel pressure acts on the first pressure chamber a through the small hole 72 of the low pressure valve body 7, and when it overcomes the elastic force of the low pressure spring 13, the low pressure valve body 7 rises. After the low pressure valve body 7 rises, the orifice 82 is closed and the air vent hole 14 is closed.
The leakage of fuel oil from is prevented. At the same time valve seat 6
The tip portion 71 of the low-pressure valve body 7 separates from the valve body 3, fuel oil flows into the high-pressure valve body 6, and fuel pressure also acts in the second pressure chamber b through the small hole 62.
In this state, the fuel pressure increases and the high pressure spring 12
When overcoming the elastic force of , the high-pressure valve body 6 rises to release the blockage in the valve portion 61, and fuel oil is injected from the narrow injection port 3' of the nozzle body 3 through the hole 4'. When the fuel oil is injected to the outside, the fuel pressure decreases, and when the pressure becomes lower than the elastic force of the high pressure spring 12, the high pressure valve body 6 descends again and the valve portion 61
The hole 4' is closed to prevent the pressure in the second pressure chamber b from increasing. The above operation is repeated to perform the desired fuel injection operation.

As mentioned above, in this type of fuel injection valve, before injecting fuel, it is necessary to supply fuel oil at low pressure to vent air and to operate a valve mechanism that blocks the passage to the exhaust hole. Therefore, to test the ventilation function and operating characteristics of the valve mechanism of the injection valve, fuel oil is supplied at low pressure, and to test the leakage state, valve opening pressure, spray state, etc., fuel oil is supplied at high pressure. must be provided.

However, in the case of the conventional air booster type fuel injection valve testing equipment, the primary air pressure from the air source is adjusted by one pressure reducing valve and then supplied to the booster driving air cylinder. Each time when switching between the low-pressure and high-pressure tests mentioned above, the operating handle of the pressure regulating valve is a screw type, so there is a time loss in adjusting it by turning it many times.Furthermore, the fuel oil pressure differs greatly between the two tests, so the high pressure Using a gauge, it was difficult to read the oil pressure in the low pressure test.

This idea was made in order to eliminate the above-mentioned drawbacks of the conventional technology.In the air supply path from the air source to the air cylinder chamber of the booster, there are two systems, one for low pressure and one for high pressure.
Two pressure regulating valves are arranged in parallel so that they can be switched by a knob, and two gauges are provided to display the fuel oil pressure, one for high pressure and one for low pressure, and at least one for low pressure among both gauges is provided. The present invention relates to a fuel injection valve testing device in which a switch for opening and closing a pressure transmission path is provided and the switch is linked to a switching switch of the pressure regulating valve.

An embodiment of this invention will be described below with reference to FIG.

In FIG. 2, 21 is a hydraulic booster, and an oil supply path 23 leading from a fuel oil tank 22 to a fuel injection valve.
a hydraulic cylinder chamber 25 adjacent to the fuel pressurizing chamber 24 and filled with hydraulic oil; and a hydraulic cylinder chamber 25 adjacent to the fuel pressurizing chamber 24 on the side opposite to the fuel pressurizing chamber 24 side. air cylinder chamber 2
6, and a plunger 29 fixed coaxially to pistons 27 and 28 located in both cylinder chambers 25 and 26, respectively, and reciprocating within the fuel pressurizing chamber 24.
It is made up of. This plunger 29 is
It is driven by the differential pressure of the air before and after the piston 28 in the air cylinder chamber 26, and as it moves back, the fuel oil is drawn from the fuel oil tank 22 into the fuel pressurizing chamber 24 through the check valve 30a. It functions to pressurize the fuel oil from the fuel pressurizing chamber 24 to the fuel injection valve as it moves forward, that is, to pressurize the fuel oil from the fuel pressurizing chamber 24 to the fuel injection valve, and to forcefully feed the fuel oil to the fuel injection valve via the check valve 30b.

Oil inlets and outlets 31a and 31b are bored in the hydraulic cylinder chamber 25 at the front and rear of the stroke of the piston 27,
Hydraulic oil passages 32, 32 are provided to connect both oil inlet/outlet ports 31a, 31b externally, and the piston 2
7, the hydraulic oil is moved between the front and rear of the piston 27 through the hydraulic oil passage 32. Reference numeral 33 denotes a control valve provided in the hydraulic oil passage 32, which is operated by a manual operation lever 34 to control the hydraulic oil passage 32.
Open and close the plunger 29 and piston 27,
Switching the reciprocating motion of 28, and plunger 29
control the forward speed of the Reference numeral 36 denotes a hydraulic oil supply tank, which is connected to the hydraulic cylinder chamber 25 before and after the stroke of the piston 27 via check valves 37a and 37b, and constantly operates the cylinder chamber 25 by replenishing hydraulic oil that decreases due to leakage, etc. It has the function of filling up with oil.

Air is supplied to the air cylinder chamber 26 from an air source 38 such as an air pump through an air supply path 39. 40 is a filter, 41a is a high-pressure pressure regulating valve that adjusts the pressure in the range of, for example, 0.5 to 8.5 Kg/cm ² , and 41b is, for example, 0.14 to 2.8 Kg/cm ²
This is a low-pressure pressure regulating valve that adjusts the pressure within the range of It is designed to convert to secondary air pressure. 43 is a check valve, 44a is a pressure gauge corresponding to the high pressure pressure regulating valve 41a, and 44b is a low pressure pressure regulating valve 41b.
The corresponding pressure gauge, 45, is an Euler.
Further, reference numerals 46 refer to air supply/exhaust ports 47a and 4 provided before and after the stroke of the piston 28 in the air cylinder chamber 26.
This is a switching valve for passing air through one of the air supply passages 30a and 30b communicating with the pilot valve 48, and is operated by air pressure from a pilot valve 48. The pilot valve 48 is equipped with an actuating rod 49, which is connected to the manual operating lever 3 of the control valve 33.
4 is in the C position, the actuating rod 49 is pressed to take the position shown in the figure, and the switching valve 46 is actuated to the state shown in the figure by the pressure of the air passing through the branch passage 50 connected to the air supply passage 39, thereby increasing the air pressure. acts on the front chamber of the piston 28, and the rear chamber is released to the atmosphere, and when the manual operation lever 34 is in the A or B position, the spring 5
1 to release the pilot air pressure to the atmosphere, the switching valve 46 is returned to the original state by the spring 47, the air pressure is applied to the rear chamber 28, and the front chamber is released to the atmosphere. 52 is a high-pressure oil pressure gauge (for example,
1000 Kg/cm ² gauge), 53 is also a low pressure oil pressure gauge (for example, 50 Kg/cm ² ), and 54 is a two-way socket installed in the pressure transmission path 55 of the low pressure oil pressure gauge 53. This two-way socket 54 is interlocked with a three-way socket 42 for switching the pressure regulating valve, and opens the pressure transmission path 55 only when the low pressure pressure regulating valve 41b is used. It functions to prevent the low pressure oil pressure gauge 53 from being destroyed by high oil pressure when using the oil pressure gauge 41a.
Opening and closing of the hydraulic oil passage 32, switching of the reciprocating motion of the plunger 29 and pistons 27 and 28, and control of the forward movement speed of the plunger 29 are performed by the manual operation lever 3.
Do it in 4. That is, by placing the manual operation lever 34 in the C position, the pilot valve 48 is switched to the state shown in the figure, and the pilot pressure acts on the switching valve 46 to switch it to the state shown in the figure.
Air pressure acts on the front chamber of the piston 28 of No. 6,
A return force acts on the piston 28. When the manual operation lever 34 is in a position other than C, the pilot valve 4
8 is switched by a spring 51, the switching valve 46 is switched by a spring 47, air pressure acts on the rear chamber of the piston 28, and a forward force acts on the piston 28. Further, when the manual operation lever 34 is in the B position, the hydraulic oil flow path 32 that communicates the front and rear chambers of the air cylinder chamber is blocked, and the movement of the piston 28 is fixed. Moreover, the hydraulic oil flow path 32 is in communication at positions other than the B position, and the piston 28 is placed in a movable state. Further, the opening area of the control valve 33 becomes maximum at the A position and the B position. Therefore, by adjusting the opening area of the control valve 33 by the movement angle of the manual operation lever 34, the forward movement speed of the piston 28 and, by extension, the plunger 29 can be controlled.

In order to test the ventilation function and operability of the fuel injection valve with the test device having the above configuration, the fuel pressurization chamber 24
First, suck the fuel oil into the Mikata Kotoku 42.
Connect the low-pressure pressure regulating valve 41b to the path, set the manual operation lever 34 to the A position, and check the air released from the air vent hole 14 of the injection valve and the fuel oil that seeps out afterward. Determine function.

Next, to find out the valve opening pressure of the low pressure valve body 7, fill the injection valve with fuel oil, and then
Connect the low-pressure pressure regulating valve 41b to the path by the three-way cock 42, move the operating lever 34 to the A position, move the plunger 29 forward, and reduce the pressure in the first pressure chamber a. reads the point at which the indicated pressure on the low-pressure oil pressure gauge 53 jumps momentarily as the pressure increases. This point indicates that the low pressure valve body 7 has operated and the valve seat 63 has opened, and the command pressure immediately before the above jump becomes the opening pressure of the low pressure valve body 7.

Furthermore, in order to know the opening pressure of the high-pressure valve body 6, after filling the injection valve with fuel oil, the fuel oil is sucked into the fuel pressurizing chamber 24, and the three-way valve 42 is filled with fuel oil.
By switching, the high-pressure pressure regulating valve 41a is connected to the path. At this time, the two-way cock 54 simultaneously operates to connect the pressure transmission path 55 of the low pressure oil pressure gauge 53.
is blocked. After that, if the manual operation lever 34 is moved to the A position in the same manner as above, the plunger 29
The indicated pressure of the high-pressure oil pressure gauge 52 increases due to the forward movement of the hydraulic pressure gauge 52, and at a certain point, the indicated pressure decreases. This indicates that the high pressure valve body 6 has opened.

Furthermore, in order to test the spray state of the injection valve, after filling the injection valve with fuel oil, the fuel oil is sucked into the fuel pressurizing chamber 24, and the high-pressure pressure regulating valve 41a is left open. When the manual operation lever 34 is set to the A position, the pressure in the second pressure chamber b in FIG. Fuel oil is injected from the narrow nozzle hole 3'. plunger 29
The high-pressure valve body 6 repeats opening several times within one stroke. When the valve is opened, observe the spray condition, and
Observe other conditions.

In each of the product tests described above, the more gradual the pressure increase state within the injection valve, the easier the various tests are. It's better to delay it.

Further, in order to operate the injection valve under the actual operating conditions of the diesel engine, the operating lever 34 may be placed in the A position, the flow rate of the hydraulic oil passage 32 may be increased, and the forward movement speed of the plunger 29 may be increased.

In the above test of the present invention, the manual operation lever 3
4 at position B, the movement of the plunger 29 can be stopped in any situation.

In the above embodiment, the driving speed of the pressurizing plunger driven by air pressure can be set to any value by adjusting the flow rate of the hydraulic oil in the hydraulic cylinder chamber, and the suitable fuel oil can be adjusted according to the type of test. It is configured so that the supply speed and pressurizing force can be applied, and the drive pressure accumulation is increased with the booster stopped and fuel is rapidly injected at high pressure to achieve a high injection speed. This idea can also be applied to boosters that do not have a hydraulic cylinder chamber. Further, although the above embodiment does not use electrical means to control the control valve 33 and the switching valve 46, this invention may employ electrical means or control means other than those illustrated.

As described above, in the fuel injection valve testing device according to this invention, two pressure regulating valves, one for low pressure and one for high pressure, are installed in the air supply path connecting the air cylinder chamber of the air-driven booster for pressurizing fuel oil and the air source. Because they are arranged in parallel and the two are switched at the same time, the fuel injection valve is equipped with a valve mechanism for fuel injection and a valve mechanism that blocks the passage to the exhaust hole after air is vented. By setting pressure regulating valves to high and low pressures suitable for the corresponding test, it is possible to switch between the two in one operation.
Furthermore, since two gauges are provided for displaying the fuel oil pressure, one for high pressure and one for low pressure, the respective oil pressure displays can be set to be easy to read when testing under high pressure and under low pressure. Furthermore, of both gauges, at least the pressure transmission path of the low-pressure gauge is provided with a switch that opens and closes the pressure transmission path, and this is linked to the switching switch of the pressure regulating valve, so that the low-pressure gauge can be destroyed by high hydraulic pressure during tests under high pressure. It is possible to prevent damage caused by forgetting to cut off the above-mentioned tip of the low pressure gauge. In addition, the device of this invention can be applied to various tests of fuel injection valves equipped with only a valve mechanism for fuel injection of other types than the B&W-GF type fuel injection valve.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a fuel injection valve used in an embodiment of this invention, and FIG. 2 is a schematic diagram of a piping system of a pressure regulating valve testing apparatus in an embodiment of this invention. ... Fuel injection valve, 21 ... Hydraulic booster, 2
2...Fuel oil tank, 24...Fuel pressurization chamber, 26
...Air cylinder chamber, 28...Piston, 2
9... Plunger, 30a, 30b... Check valve, 38... Air source, 41a... Pressure regulating valve for high pressure of air, 41b... Pressure regulating valve for low pressure of air, 42... Three-way cock (air supply) selection switch), 46...switching valve, 47a, 47b...
Supply/exhaust port, 52... High pressure oil pressure gauge, 53...
Hydraulic pressure gauge for low pressure, 54...Two-way kettle (switching kettle for oil pressure gauge).

Claims (1)

[Scope of utility model registration request] A hydraulic booster comprising a fuel pressurizing chamber that communicates with a fuel injection valve and a fuel tank of a fuel oil source through check valves, and an air cylinder chamber in which a piston for reciprocating a plunger is disposed within the fuel pressurizing chamber. and 2 for high pressure and low pressure that display the oil pressure of fuel oil supplied to the fuel injection valve.
a hydraulic pressure gauge switch that opens and closes the pressure transmission path of at least the low pressure hydraulic pressure gauge, and high pressure and low pressure pressure gauges arranged in parallel on the air supply path from the air source to the air cylinder chamber. two pressure regulating valves for the pressure regulating valves, a switching knob for selecting the supply pressure that switches the air supply path communicating with both pressure regulating valves and is linked to the switching knob for the oil pressure gauge, and a supply pressure that is supplied via the two pressure regulating valves. A switching valve is provided for alternately supplying air to the air supply and exhaust ports at both ends of the air cylinder chamber, and fuel oil flows from the fuel oil source into the fuel pressurizing chamber as the plunger moves back. A fuel injection valve testing device characterized in that the fuel is pressurized as it moves forward and is force-fed to the fuel injection valve, and the degree of pressurization can be selected by switching between two pressure regulating valves.