JPH034782Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a multi-fuel high-pressure injection device for injecting various fuels at high pressure.

(Prior art and its problems) Conventionally, the plunger of a distributor is driven by the pressure of main fuel such as heavy oil sent from a fuel injection pump, and this plunger injects the main fuel and auxiliary fuel such as water into two injections. A device is known in which fuel is sent to a nozzle at different timings and injected into a cylinder in two stages, and the purpose of this device is to improve the combustion efficiency of heavy oil, which is the main fuel.

In addition, as shown in Japanese Patent Application Laid-Open No. 58-77160,
The metered fuel is led to a pressure booster, and the fuel in the pressure booster is pressurized with hydraulic oil and injected from an injection nozzle.
A system has been proposed in which the hydraulic pressure applied to the pressure booster is switched using a solenoid valve to automatically control the fuel injection timing.

Furthermore, attempts have been made to use the same fuel and inject it into the same cylinder from two fuel injection pumps with two nozzles to improve combustion efficiency as a pilot injection, or by using the same fuel injection pump,
Various methods have been devised, including two-stage injection methods depending on the shape of the cam.

In these conventional technologies, two nozzles are required for one cylinder, or it is not possible to obtain high pressure, or even if high pressure can be obtained, the control means uses a solenoid valve or the like. Electrical components were required, and there were many problems such as the diesel engine not being able to achieve its original characteristic of not requiring electrical components, and being complicated and being only applicable to the same type of fuel.

(Purpose of the invention) This invention was made in view of the above points.
To provide a multi-fuel high-pressure injection device capable of injecting various fuels at high pressure with one nozzle and controlling the injection amount and injection timing without using electrical equipment such as a solenoid valve.

(Summary of the invention) In order to achieve the above object, the invention includes a metering section that measures and delivers the first fuel and the second fuel separately, and a pressure increaser that increases the pressure of each of the fuels separately, and a pressure generation control unit that generates a working pressure to be supplied to each of the pressure increasers and controls the generation timing of each working pressure depending on the operating state of the engine. and a first fuel cell through which the first fuel among the fuels respectively pressure-intensified by the pressure-increasing parts is passed.
a needle valve that opens and closes the injection passage and the first injection passage; a second injection passage that is connected to the first injection passage through the needle valve and passes the second fuel; and an injection nozzle including a check valve provided between the injection passage and the second injection passage.

(Example) An example of the present invention will be described below in detail based on the drawings.

As shown in FIG. 1, the multi-fuel high-pressure injection device according to the present invention includes a metering section 1, a pressure increasing section 2 that increases the pressure of the fuel sent from the metering section 1, and a pressure generation control section that controls these. 3 and an injection nozzle 4 that injects pressurized fuel.

The metering unit 1 has a tank 5 for storing the first fuel A and a tank 5' for storing the second fuel B, and the metering unit 1 has a tank 5 for storing the first fuel A and a tank 5' for storing the second fuel B. It is connected to pumps 8, 8'. Plungers 10, 10' of the metering pumps 8, 8' reciprocate by cams 9, 9' of camshafts that rotate in synchronization with the rotating shaft of an engine (not shown).
The effective strokes of 0 and 10' are achieved by rotating the plungers 10 and 10' by the governor 11 through the injection quantity control racks 12 and 12' and control sleeves (not shown).
The metering pumps 8, 8' are connected to the pressure increaser 2 via flow paths 13, 13' and delivery valves 14, 14'.

The pressure generation control unit 3 has a hydraulic oil tank 15 that stores hydraulic oil, and has a hydraulic oil tank 15 that stores hydraulic oil. They are connected to control pumps 18 and 18', respectively. The timing control pumps 18, 18' are the flow pumps 8, which rotate in synchronization with the rotating shaft of the engine.
The main plungers 20, 20' are reciprocated by cams 19, 19' on a cam shaft other than the cam shafts of the cams 9, 9', and the main plungers 20, 20'
The effective stroke of the plunger 20, 2 is determined by the control lever via the injection amount control racks 21, 21' and the control sleeve.
0'. Further, the injection timing is determined by rotating the sub-plungers 23, 23' using the timing control lever via the timing racks 22, 22' and the timing control sleeve. The timing control pumps 18, 18' each have a flow path 2 in the pressure increasing section 2.
4 and 24', and the overflowing hydraulic oil is connected to the hydraulic oil tank 15 through a flow path 25.

The pressure intensifier 2 is composed of two pressure intensifiers 30 and 30' and has the same structure. The pressure intensifiers 30, 30' have large diameter bores 30a, 30'a, and small diameter bores 30b, 30'b formed concentrically at one end thereof.
A large diameter piston 30c slidably fitted into each bore,
30'c and small diameter pistons 30d and 30'd. The small diameter bore 30b is connected to the main inlet hole 31a of the main injection passage 31 of the injection nozzle 4, and the small diameter bore 3
0'b is connected to the sub-inlet hole 32a of the sub-injection passage 32 of the injection nozzle 4 through channels 33 and 34, respectively.

Next, the configuration of the main parts of the timing control pump 18 will be explained. Note that the timing control pump 18' has the same configuration as the timing control pump 18.

FIG. 2 shows a longitudinal section of a timing control pump 18 to which the present invention is applied. A plunger barrel 41 is fitted inside a pump housing 40 of the timing control pump 18, and the plunger barrel 41 also functions as a suction port. It has an overflow port 41a and a timing port 41b. The overflow port 41a and the timing port 41b communicate through a hydraulic oil reservoir chamber 42 formed by a recess provided in the upper inner peripheral surface of the pump housing 40 and the corresponding outer peripheral surface of the plunger barrel 41. are doing. The hydraulic oil reservoir chamber 42 is connected to the inlet port 4 of a fuel supply nipple 43 that communicates with the outside.
3a is connected to the oil feed pump 16 shown in FIG. The main plunger 20 and the sub plunger 23 are fitted into the plunger barrel 41 so as to be movable together in the axial direction and rotatable separately in the circumferential direction. The sub-plunger 23 is located concentrically on the outside of the main plunger 20, and has a head 20b in which an injection amount setting lead 20a of the main plunger 20 is carved, and a step 2 below the main plunger 20.
A timing setting lead 23a for adjusting the injection start timing is cut out at the upper end.

The timing control sleeve 44 is rotatably fitted to the lower part of the plunger barrel 41, and a pinion 44a carved on the outer peripheral surface of the upper end engages with the timing rack 22, and is inserted into a slit 44b provided along the axial direction in the lower part. is the sub-plunger 23
The collar portion 23b is inserted.

The injection amount control sleeve 45 is rotatably fitted onto the timing control sleeve 44, a pinion 45a carved on the outer peripheral surface of the upper end meshes with the injection amount control rack 21, and a slit 45b provided along the axial direction on the lower part. The flange 20d of the main plunger 20 is fitted inside.

A plunger guide 46 is fitted into the lower open end of the pump housing 40, and is prevented from coming off by a snap spring 47, and the tip end surface 20e of the main plunger 20 is in contact with the inner end surface. A plunger spring 50 is interposed concentrically between the plunger guide 46 and the outside of the injection amount control sleeve 45 and the step between the pinion 45a and the plunger guide 46 via spring seats 48 and 49.

An equal-pressure type delivery valve 51 is fixed to the plunger barrel 41 at the upper open end of the pump housing 40 by bolts (not shown), and forms a pump chamber 52 with the head 20b of the main plunger 20, and the same-pressure type delivery valve 51 is fixed to the plunger barrel 41 by bolts (not shown). The valve 51 is constructed with a valve holder 53 and a valve seat 54 in contact with each other, and a discharge passage 55 and a return passage 56 are formed in the delivery valve 51, and these passages merge near the delivery end. A discharge side check valve 57 is disposed within the valve seat 54 in the discharge passage 55.
A return check valve 58 is disposed in the valve holder 53 in the return passage 56, respectively. The discharge side check valve 57 includes a valve body 57a, a threaded spiral seat 57b screwed onto the valve seat 54, and the valve body 57.
Valve spring 57 interposed between a and the seat 57b
c, and the valve body 57a is configured by the pump chamber 52.
The valve is closed by being biased toward the side. The return side check valve 58 includes a valve body 58a, a threaded spring seat 58b screwed onto the valve holder 53, and the valve body 58.
the valve spring 58 interposed between a and the seat 58b;
The valve body 58a is biased toward the delivery side and closed.

The timing control valve 18' is also constructed similarly to the timing control valve 18.

Next, the configuration of main parts of the injection nozzle 4 will be explained.

As shown in FIGS. 1 and 3, the injection nozzle 4 includes a nozzle body 72 composed of an upper body 70 and a lower body 71, and a nozzle body 72 disposed in an axial hole of the nozzle body 72 and connected to the main injection passage 31. A needle valve 73 that opens and closes, and a main injection passage 31 to the sub injection passage 32.
The needle valve 73 includes a check valve 74 that prevents fuel from flowing back into the needle valve 73, and a pressure spring 75 that presses the needle valve 73. The nozzle body 72 is inserted into a cylinder head (not shown).

The upper main body 70 has a shaft hole 70a, into which a connecting rod 76 is slidably inserted.
6 urges the needle valve 73 downward by a pressing spring 75, and furthermore, a hole 70b forming the main injection passage 31 and a hole 70c forming the sub injection passage 32 are bored in the upper body 70, respectively. , the hole 7
0b has one end open to the main inlet hole 31a, connected to the pressure intensifier 30 via a flow path 33, and the other end opened to the lower main body 71. The hole 70c opens at one end to the sub-inlet hole 32a, and is connected to the pressure intensifier 30' and the flow path 34.
The other end opens into an auxiliary fuel reservoir chamber 77 having a slightly larger diameter than the shaft hole 70a.

The lower body 71 has a center hole 71a formed in its axis, and the needle valve 73 and the valve seat body 78 are slidably inserted in the abutting state, and the needle valve 73 is inserted into the connecting rod 7.
6, the main sheet surface 7 is formed into a tapered shape.
1b is pressed. One end of the center hole 71a opens into the auxiliary fuel reservoir chamber 77 formed to have a slightly larger diameter than the hole 71a, and the other end opens into the main fuel reservoir chamber 79.The lower end of the main seat surface 71b has an outlet chamber 80.
is provided concentrically with the center hole 71a, and a plurality of injection ports 71c are formed from the outlet chamber 80 at a predetermined angle at the tip of the nozzle body 72.

Furthermore, a hole 71d constituting the main injection passage 31 is bored in the lower body 71, and one end of the hole 71d is formed in the upper body 71.
0, and the other end opens to the main fuel reservoir chamber 79.

The needle valve 73 and the valve seat body 78 are slidably inserted into the center hole 71a of the lower main body 71, and one end of the needle valve 73 is connected to the main sealing surface 7.
It has a tapered surface 73a corresponding to 1b, and the surface 73a is seated on and off the main seat surface 71b to open and close the main injection passage 31. An outer peripheral surface 73b of the needle valve 73 facing the main fuel reservoir chamber 79
The outer diameter of the lower body 71 is smaller than the outer diameter of the outer circumferential surface 73c that comes into sliding contact with the center hole 71a of the lower main body 71, and the boundary surface thereof is tapered.
d is provided. The other end of the needle valve 73 is in contact with a valve seat body 78, and a large diameter hole 73e and a small diameter hole 73f are concentrically formed through the axis of the needle valve 73. , opens facing the valve seat body 78, and the small diameter hole 73f opens facing the outlet chamber 80. The valve seat body 78 has a hole 78 in the fitting axis.
A and a hole 78b having a slightly larger diameter than the hole 78a are concentrically bored, and the hole 78a communicates with the auxiliary fuel chamber 77, and a check valve 74 is fitted into the large diameter hole 78b. ing. The check valve 74 is a needle valve 73
The check valve is housed in a check valve storage chamber 81 formed by a hole 73e of the valve body 78 and a hole 78b of the valve seat body 78, which has a diameter slightly smaller than that of the hole 73e.
3 and a spring 84 interposed between the valve body 82 and the spring receiver 83. The valve body 82 is fitted into a hole 78b of the valve seat body 78, and the hole 78b is connected to the large diameter hole 73e of the needle valve 73.
The valve body 82 has a slightly smaller diameter and forms a stepped portion, and the valve body 82 is seated on the stepped valve seat body 78. The spring receiver 83 is slidably inserted into the hole 73e of the needle valve 73, and a hole 83a is bored in the approximate center of the spring receiver 73e in the axial direction.
A spring 84 is disposed between the spring receiving seat 83b provided approximately in the center and one end of the valve body 82.
is interposed and the valve body 82 is pressed against the valve seat body 78.
sit down. Note that there is a predetermined distance between the end faces facing the valve body 82 and the spring receiver 83, and the maximum lift amount of the check valve 74 is regulated.

(Function) First fuel A (for example, main fuel) and second fuel B
The fuel (for example, auxiliary fuel) is sent from tanks 5, 5', respectively, to metering pumps 8, 8' via channels 7, 7' by delivery pumps 6, 6', as shown in FIG. The metering pumps 8, 8' send fuel A and fuel B to the flow paths 13, 10, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 11, 11, 11, 11, 11, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11 be caused by plungers 10, 10' that reciprocate by the cams 9, 9' of the camshaft that rotate in synchronization with the rotating shaft of the engine. 13' and delivery valves 14, 14' to pressure intensifiers 30, 30', respectively. In this case, the effective stroke of the plungers 10, 10', that is, the injection amount is controlled by the governor 11 via the injection amount control racks 12, 12' and the control sleeve.
0', and the injection timing of fuel A and fuel B is determined by the preset cam 9 of the camshaft.
This can also be done by shifting the lift position of 9'.

Fuel A sent to pressure booster 30 and pressure booster 30'
The fuel B sent to the timing control pumps 18 and 1, which form the main body of the pressure generation control section 3, respectively
8' via pressure intensifiers 30, 30'. An oil feed pump 16 driven by a power source taken from the rotating shaft of the engine supplies hydraulic oil from a hydraulic oil tank 15 storing hydraulic oil through a flow path 17 to a timing control pump 18 as shown in FIG. The fuel is supplied to the inlet port 43a of the fuel supply nipple 43. The hydraulic oil flows from the nipple 43 to the hydraulic oil reservoir chamber 4.
2. It is supplied to the pump chamber 52 via the overflow port 41a. The main plunger 20 of the timing control pump 18 is pushed up against a plunger spring 50 via a plunger guide 46 by a camshaft 19 that rotates in synchronization with the rotating shaft of the engine, compressing the hydraulic oil in a pump chamber 52. Then, the valve body 57a is pushed up against the valve spring 57c of the discharge side check valve 57 of the equal-pressure type delivery valve 51, and hydraulic oil is forcefully delivered to the large diameter bore 30a of the compressor 30. In this case, the main plunger 20 is rotated by the injection charge control rack 21 via the control sleeve 45, and the injection amount is set by the injection amount setting lead 20a of the head 20b and the overflow port 41a of the plunger barrel 41. On the other hand, the secondary plunger 23 is rotated by the timing rack 22 via the control sleeve 44, and the main plunger 23 is rotated by the timing setting lead 23a provided on the head and the timing port 41b of the plunger barrel 41.
0 to start compressing the hydraulic oil in the pump chamber 52, that is, adjust the injection start timing.

In FIG. 1, the hydraulic oil pumped into the large diameter bore 30a pushes up the large diameter piston 30c, so the small diameter piston 30d
The fuel A that has been pumped into the fuel tank b is pumped through the flow path 33 to the main inlet port 31a of the injection nozzle 4. The fuel B is delivered to the injection nozzle 4 through the flow path 34 by the timing control pump 18' and the pressure intensifier 30' in the same manner as the timing control pump 18 and the pressure intensifier 30, with a slight delay from the timing of the fuel A. is fed under pressure to the sub-inlet port 32a.

The injection amount and injection start timing may be determined manually, by a governor, or by electronic control means.

The fuel A that has reached the main inlet port 31a passes through the main injection passage 31 into the main fuel reservoir chamber 79 shown in FIG.
The needle valve 73 is opened by pressing the tapered surface 73d provided on the needle valve 73 against the pressure spring 75 shown in FIG. The opening time of the needle valve 73 is determined by the metering pump 8.
determined by the amount of fuel A delivered by
The metered fuel A is delivered to the injection hole 71 of the injection nozzle 4.
c is injected into the engine cylinder.

Fuel B, which reaches the auxiliary inlet port 32a a little later than the timing of the fuel A, enters the auxiliary fuel chamber 77 through the passage 70c and enters the valve body 83 of the check valve 74.
is pressed, the valve body 82 of the check valve 74 is opened against the spring 84, and the fuel B reaches the outlet chamber 80 and is injected in the same amount as the fuel A, slightly later than the timing of the fuel A. It is injected from the injection hole 71c of the nozzle 4 into the cylinder of the engine. In this way, fuel A
Since fuel B is injected immediately after the injection of fuel B, the characteristics of the fuels complement each other in the cylinders of the engine, good combustion characteristics can be obtained, and thermal efficiency can be improved.

After the fuel A has been injected, the fuel A is again sent to the small diameter bore 30b of the pressure booster 30 by the metering pump 8 via the flow path 13 and the delivery valve 14, and returns the small diameter piston 30b to its original position. The large diameter piston 30c is also returned to its original state, and the hydraulic oil in the large diameter bore 30a is transferred to the passage 2.
4 of the return side check valve 58 of the equal pressure type delivery valve 51 of the timing control pump 18
8c, push up the valve body 58a and pump chamber 52
Go back inside. Since the inside of the pump chamber 52 is always filled with hydraulic oil, the hydraulic oil reaches the outlet port 43b via the overflow port 41a and the nipple 43, and returns to the hydraulic oil tank 15 via the flow path 25. Fuel B
The same operation as in the case of fuel A is performed, and the hydraulic oil returns to the hydraulic oil tank 15.

In the timing control pump 18 again, the main plunger 20 compresses the hydraulic oil in the pump chamber 52 by the cam 19 of the camshaft, opens the discharge side check valve of the equal pressure type delivery valve 51, and opens the large diameter of the pressure intensifier 30. Boa 3
Send hydraulic oil to 0a. The timing control pump 18' is also the timing control pump 18.
Perform the same operation as above to pump the hydraulic oil into the large diameter bore 30'
Send to a. Thereafter, the above operation is repeated to inject fuel A and fuel B one after another into the cylinder of the engine from the injection hole 71c of the injection nozzle 4.

(Effect of the invention) As explained above, according to the invention, there is a metering section that separately meters and sends out the first fuel and the second fuel, and a a pressure increasing section that increases the pressure of each fuel separately; a pressure generation control section that generates a working pressure to be supplied to each of the pressure increasing sections and controls the generation timing of each working pressure depending on the operating state of the engine; A first injection passage through which the first fuel of each fuel whose pressure has been increased by each pressure increaser is passed; a needle valve that opens and closes the first injection passage; and a needle valve that opens and closes the first injection passage; A second injection passage connected to the first injection passage and passing the second fuel, and a check valve provided between the first injection passage and the second injection passage. Since it is composed of an injection nozzle, it is possible to freely control the injection amount and injection timing of various fuels at high pressure with one injection nozzle, without using electrical components such as solenoid valves. I can do it. Moreover, since the configuration is simple, it is easy to assemble into the engine.
It has many advantages such as improving combustion efficiency.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
FIG. 2 is a longitudinal cross-sectional view of a timing control pump according to the present invention, and FIG. 3 is a vertical cross-sectional view showing an injection nozzle according to the present invention. DESCRIPTION OF SYMBOLS 1... Metering part, 2... Pressure increase part, 3... Pressure generation control part, 4... Injection nozzle, 31... First injection passage, 32... Second injection passage, 73... Needle Valve, 74...Check valve.

Claims (1)

[Scope of utility model registration request] a metering section that separately meters and sends out the first fuel and the second fuel, a pressure increasing section that increases the pressure of each fuel from each metering section, and each of the pressure increasing sections. a pressure generation control section that generates a working pressure to be supplied to the engine and controls the generation timing of each working pressure in accordance with the operating state of the engine, and each of the fuels whose pressure is increased by each of the pressure increasing sections. A first injection passage for passing the first fuel, a needle valve for opening and closing the first injection passage, and a second injection passage connected to the first injection passage through the needle valve for passing the second fuel. An injection nozzle comprising a second injection passage through which the fuel passes, and a check valve provided between the first injection passage and the second injection passage. High pressure injection device.