JPH0417808Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a fuel injection system for internal combustion engines, particularly diesel engines.

In a conventional in-line fuel injection pump for diesel engines, a barrel is housed within the pump housing, and a pump chamber with a spring-loaded discharge valve is provided within the barrel, with one end facing the pump chamber and the other end facing the engine. a plunger operatively connected to a cam driven by the plunger, and a control sleeve is fitted around the plunger so as to be slidable in the axial direction, and the control sleeve is constantly supplied with fuel by a feed pump. For example, 1975 patent application No. 37541
No. (filed on March 29, 1978). In this known device, a control groove is provided on the control sleeve that is inclined with respect to the axis of the plunger, and one end opens into the pump chamber and the other end opens near the lower end surface of the control sleeve to form a control hole. A passage is provided in the plunger, and the plunger is rotated around its axis to change the relative position of the control hole with respect to the control groove to adjust the fuel injection amount, and is rotatably supported in the housing. The rotation of the eccentric pin on the camshaft displaces the control sleeve in the axial direction of the plunger and adjusts the injection timing. A control rack for rotating the control sleeve around the axis of the plunger for adjusting the fuel injection amount, and a camshaft and an eccentric pin for adjusting the fuel injection timing are arranged on both sides of the control sleeve in the diametrical direction. This resulted in a complicated structure and a problem in that the width of the injection pump (the dimension perpendicular to the row of plungers arranged in parallel according to the number of cylinders) became large.

In order to solve the above problems, a fuel injection device in which fuel injection amount and fuel injection timing adjusting means are disposed on one side of a control sleeve has already been proposed in Japanese Utility Model Application No. 196257/1983. This previously proposed device engages an adjustment pin protruding from an adjustment rod into a fitting hole formed in a control sleeve, and rotates the adjustment rod using a complex link mechanism to adjust the fuel injection amount. and is configured to adjust the injection timing.

However, in this device, the depth of the fitting hole drilled in the control sleeve is limited by the wall thickness of the control sleeve that is allowed in the design, so the amount of rotation around the axis of the sleeve and the axis The disadvantage is that the amount of displacement in the direction cannot be set sufficiently large, and the degree of freedom in adjusting the injection amount and timing is small.
Furthermore, each component requires a high degree of processing accuracy, and the structure is complex and the number of parts is extremely large, resulting in high manufacturing costs.

This invention was devised in view of the above circumstances.
A barrel stored in the housing, a plunger slidably inserted in the barrel in the axial direction, a spring-loaded discharge valve mounted in the barrel, and the discharge valve and one end surface of the plunger. a pump chamber confined within the barrel; a fuel chamber within the barrel formed around the plunger; a control sleeve slidably fitted outside the plunger within the fuel chamber; An oil passage in the plunger that opens, and a control provided on one side of the outer circumferential surface of the plunger and the control sleeve at an angle with respect to the axis of the plunger in order to communicate or block communication between the pump chamber and the fuel chamber via the oil passage. groove,
A flow rate adjustment pin provided on the other side of the outer circumferential surface of the plunger and the control sleeve, fixed to one side of the control sleeve and extending in the axial direction of the plunger; an injection timing adjustment pin, an engagement member having first and second grooves that slidably engage with the flow rate adjustment pin and the injection timing adjustment pin, respectively; a control shaft member on which the engagement member is mounted; an injection amount control member that rotates the control sleeve around the plunger axis via the flow rate adjustment pin that is engaged with the first groove of the engagement member by driving the control shaft member in the axial direction; and an injection for displacing the control sleeve in the plunger axial direction via the injection timing adjustment pin engaged with the second groove of the engagement member by rotating the control shaft member around its axis. The gist of the present invention is a fuel injection device characterized by comprising a timing control member.

A first embodiment of the present invention will be specifically described below with reference to FIGS. 1 and 2. 10 is a housing of a fuel injection pump, 12 is a barrel fitted into the upper end of the housing so as to be freely removable, 14 is a pump chamber formed in the barrel 12, and 16 is screwed to the upper end of the barrel. The pump chamber 14 is housed in a discharge valve holder 18 and preloaded by a spring 20.
A fuel discharge valve 22 is provided in the discharge valve holder 18 and communicates with a fuel injection nozzle via a fuel injection pipe (not shown), and a discharge passage 24 is slidable into the housing 10 via the barrel 12. A plunger fitted in the upper end surface 2 of the plunger.
4a faces the pump chamber 14, and its lower end 2
4b is in contact with the cam 30 via the cam holder 26 and the roller 28. 32 is a camshaft driven by an engine (not shown); 34 is a spring that constantly presses the cam holder 26 against the cam 30;
A fuel chamber 6 is formed surrounding the plunger 24, and is constantly supplied with fuel by a feed pump (not shown) while the engine is operating. 38 is the plunger 2 in the same fuel chamber 36.
A cylindrical fuel control sleeve 40 is fitted around the outer circumference of the sleeve 38 so that it can freely slide in the axial direction and rotate freely, and an L-shaped flow rate sleeve 40 has one end fixed to the outer circumference of the sleeve 38. An injection timing adjustment pin 42, which is an adjustment pin and extends perpendicularly to the plunger axis, is fixed on a vertical pin 40a that extends in the plunger axis direction. Reference numeral 44 generally indicates a control shaft member that cooperates with the injection amount adjustment pin 40 and injection timing adjustment pin 42, and as shown in detail in FIG. An injection amount control member 46 is connected to an appropriate actuator to be displaced in the directions of arrows A and A' in the figure, and is engaged with the injection amount control member so as to be freely inserted into and removed from it in the axial direction, and The injection timing control member 48 is connected to a suitable actuator, such as a rotary solenoid (not shown), so that the injection amount control member 46 is rotated around its axis by rotation. ing. Reference numeral 50 denotes an engaging member provided in the rectangular cross section of the injection amount control member 46 to protrude toward the control sleeve 38, and is a first engaging member that slidably engages with the vertical pin 40a of the flow rate adjusting pin 40. It includes a groove 52 and a second groove 54 that slidably engages with the injection timing adjustment pin 42 . 56 has one end connected to the pump chamber 14
An oil passage in the plunger that opens at the bottom and communicates with a control groove 58 cut into the outer peripheral surface of the plunger, the other end of which is in contact with the inner peripheral surface of the control sleeve.
8 has a portion inclined with respect to the plunger axis and a portion extending in the direction of the plunger axis, and the overall diameter is λ.
(lambda) shaped like a letter. 60 is a control hole bored in the radial direction on the control sleeve 38 and cooperates with the control groove 58; 62 is a plunger 2;
A hollow tubular plunger guide is fitted to the lower end portion of the plunger guide 4, and the square section 64 at the lower end thereof is fitted into the corresponding square section 24c on the plunger 24. As a result, the plunger 24 is connected to the barrel 12 and Although it can be freely displaced in the axial direction with respect to the plunger guide 62, it cannot rotate relative to the plunger guide 62 around the axis. A projection 66 having an axial engagement groove is provided on the outer peripheral portion of the upper end flange of the plunger guide 62. On the other hand, an adjustment member 70 having an eccentric pin 68 that fits into the engagement groove is rotatably fitted on the wall surface of the housing 10 facing the protrusion 66, and the adjustment member 70 protrudes outside the housing. A lock nut 72 is screwed into the threaded portion.

In the above device, when each member of the fuel pump is in the illustrated position, the control hole 60 and the control groove 58 do not communicate with each other, and the lower end of the control groove 58 is connected to the control sleeve 38.
The pump chamber 14 and the fuel chamber 36 are in communication with each other because the pump chamber 14 protrudes downward from the lower end surface and opens into the fuel chamber 36 . From this state, the engine will move the camshaft 3
2 is rotated and the plunger 24 is pushed upward by the cam 30 via the roller 28, the lower end of the control groove 58 is closed by the control sleeve 38, and the inclined portion of the control groove and the control hole are closed. Since the communication between the pump chamber 14 and the fuel chamber 36 is cut off, the communication between the pump chamber 14 and the fuel chamber 36 is cut off. Therefore, plunger 2
4 pressurizes the fuel in the pump chamber, and when the pressure exceeds a set value, the discharge valve 16 is opened and fuel is supplied from the discharge passage 22 to the injection nozzle of the engine. When the plunger 24 rises further and the inclined groove portion of the control groove 58 communicates with the control hole 60 of the control sleeve 38, the pump 14 communicates with the fuel chamber 36 again and fuel injection ends. Thereafter, the upper end of the axial portion of the control groove 58 projects upward from the upper end surface of the control sleeve 38 to directly communicate the pump chamber 14 and the fuel chamber 36, thereby reliably preventing two-stage injection. Next, when the actuator moves the injection amount control member 46 in its axial direction, for example in the direction of arrow A in FIG. The flow adjustment pin 40 and therefore the control sleeve 38 are rotated clockwise around the axis of the plunger 24 by the cooperative action, and the relative position between the control hole 60 and the control groove 58 is changed, thereby controlling the fuel supply. The amount is increased or decreased. Further, when the injection timing control member 48 is rotated around its axis by the aforementioned appropriate actuator, such as a rotary solenoid, the engagement member 50 is rotated around the axis of the control shaft member 44, and the second groove 54 and the injection timing control member 48 are rotated. The control sleeve 38 is displaced in the axial direction of the plunger 24 by cooperation with the timing adjustment pin 42, and the relative position of the control hole 60 and the control groove 58 in the cam lift direction changes, that is, the injection timing is adjusted. Become. According to this configuration, the member that controls the injection amount by rotating the control sleeve 38 around its axis and the member that controls the injection timing by displacing the control sleeve 38 in the axial direction are Since it is disposed on one side of the control sleeve 38 in the radial direction, the structure is simpler than that of the conventional device, and there is an advantage that the lateral dimension of the control sleeve 38 portion can be reduced.

Additionally, a flow rate adjustment pin 40a and an injection timing adjustment pin 4 are fixed to the outer peripheral surface of the control sleeve 38.
2 and the first and second grooves 52 and 54 of the engaging member 50
Since the injection amount and injection timing are controlled in cooperation with the Also, there is an advantage that there is a large degree of freedom in adjusting the injection timing. In addition, the structure is significantly simpler and the number of parts is smaller than that of previously proposed devices, and a high degree of machining accuracy is not required for the pins 40a, 42 and the grooves 52, 54 of the engaging member 50, so manufacturing costs are reduced. It has the advantage of being cheaper.

Next, in the above-described fuel injection device, when aligning and matching the injection amounts of the injection pumps of a plurality of cylinders, the lock nut 72 is loosened and the adjustment member 70 is rotated using a tool such as a screwdriver. .
Then, due to the cooperation between the eccentric pin 68, the protrusion 66, and the engagement groove, the plunger guide 62 moves toward the plunger 2.
4 in an appropriate direction around the axis of the plunger, and the relative position of the plunger with respect to the control sleeve 38 is changed, in other words, the relative position of the control hole 60 with respect to the control groove 58 is changed, so that each cylinder The injection amount of the fuel injection pump is finely adjusted in accordance with the above. After the injection amounts of the injection pumps of all cylinders are matched in this way, when the lock nuts 72 of each adjustment member 70 are tightened to fix each adjustment member 70 to the housing 10, the eccentric pin 68 and the protrusion 66 are engaged. The plunger guide 62 is connected to the plunger 24 via the matching groove.
will be correctly associated with each corresponding control sleeve 38. As a result, there is an advantage that the injection amount of the fuel injection pump can be quickly and easily finely adjusted and matched for each cylinder.
In addition, the injection timing of a multi-cylinder injection pump can be adjusted by () adjusting the shim on the tightening surface between the barrel 12 and the housing 10 () adjusting the shim between the cam holder (tapepet) 26 and the plunger lower end 24b. This can be done by adjusting the In the above-mentioned embodiment, a control groove 58 is provided on the plunger 24, and a cooperating control hole 60 is provided on the control sleeve 38. However, similar to the known device, there is a hole on the control sleeve 38 side along the axis of the plunger. On the other hand, even in a device configured to provide an inclined control groove and open a control hole communicating with the oil passage 52 on the outer peripheral surface of the plunger 24,
The present invention can be similarly applied.

Next, a second embodiment of the present invention will be described with reference to FIG. Reference numeral 46' denotes an injection amount control member having a circular cross section, on which an engaging member 50' having a first groove 52' and a second groove 54' is mounted, and is controlled by an adjusting bolt 74 and a nut 76. Fixed. Therefore, the injection amount can be adjusted by rotating the control sleeve 38 by displacing the injection amount control member 46' in the axial direction as in the first embodiment, and by rotating it around the axis. The injection timing can be adjusted by moving the control sleeve 38 up and down. Initial alignment of a multi-cylinder injection pump can be performed by loosening the nut 76 and moving the engagement member 50' in the axial direction to adjust the injection amount and the angle around the axis of the engagement member 50'. By adjusting the positions, the injection timings can be matched.

As mentioned above, the fuel injection device according to the present invention has the following features:
A barrel stored in the housing, a plunger slidably inserted in the barrel in the axial direction, a spring-loaded discharge valve mounted in the barrel, and the discharge valve and one end surface of the plunger. a pump chamber confined within the barrel; a fuel chamber within the barrel formed around the plunger; a control sleeve slidably fitted outside the plunger within the fuel chamber; An oil passage in the plunger that opens, and a control provided on one side of the outer circumferential surface of the plunger and the control sleeve at an angle with respect to the axis of the plunger in order to communicate or block communication between the pump chamber and the fuel chamber via the oil passage. groove,
A control hole provided on the outer circumferential surface of the plunger and the other side of the control sleeve and cooperating with the control groove, a flow rate adjustment pin fixed to one side of the control sleeve and extending in the axial direction of the plunger, and a plunger fixed to the flow rate adjustment pin. An engagement member having an injection timing adjustment pin extending substantially perpendicular to the axis, first and second grooves that slidably engage the flow rate adjustment pin and the injection timing adjustment pin, respectively; and a control shaft member on which the control sleeve is mounted, and by driving the control shaft member in the axial direction, the control sleeve is moved around the plunger axis via the flow rate adjustment pin that is engaged with the first groove of the engagement member. The above-mentioned control is performed through the injection amount control member which is rotated to rotate the control shaft member, and the injection timing adjustment pin which is engaged with the second groove of the engagement member by rotating the control shaft member around its axis. It is characterized by being equipped with an injection timing control member that displaces the sleeve in the axial direction of the plunger.It has a simple structure, can be manufactured at low cost, has a large degree of freedom in adjusting the fuel injection amount and injection timing, and is easy to install. It is extremely advantageous to be able to provide a device of this type that requires less space.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the entire device showing the first embodiment of the present invention, FIG. 2 is a perspective view showing the control sleeve 38 and control shaft member 44 of FIG. Control shaft member 44' in second embodiment
FIG. 10...housing, 12...barrel, 14...
...Pump chamber, 16...Discharge valve, 24...Plunger, 30...Cam, 36...Fuel chamber, 38...Control sleeve, 40...Flow rate adjustment pin, 42...Injection timing adjustment pin, 44... Control shaft member, 46...
Injection amount control member, 48... Injection timing control member, 5
0...Engagement member, 58...Control groove, 60...Control hole.

Claims (1)

[Scope of utility model registration request] A barrel stored in the housing, a plunger inserted into the barrel so as to be slidable in the axial direction,
a spring-loaded discharge valve mounted within said barrel;
A pump chamber bounded within the barrel by the discharge valve and one end surface of the plunger; a fuel chamber within the barrel formed surrounding the plunger; a pump chamber that is slidably fitted outside the plunger within the fuel chamber; an oil passage in the plunger whose one end opens into the pump chamber; an outer circumferential surface of the plunger and one of the control sleeves for communicating or blocking communication between the pump chamber and the fuel chamber via the oil passage; a control groove provided at an angle with respect to the axis of the plunger; a control hole provided on the outer peripheral surface of the plunger and the other side of the control sleeve and cooperating with the control groove; and a control hole fixed to one side of the control sleeve and extending in the direction of the axis of the plunger. an injection timing adjustment pin fixed to the flow rate adjustment pin and extending substantially perpendicular to the axis of the plunger; an engaging member having a second groove; a control shaft member on which the engaging member is mounted; and a control shaft member that is engaged with the first groove of the engaging member by driving the control shaft member in the axial direction. an injection amount control member that rotates the control sleeve around the plunger axis via the flow rate adjustment pin; and a second groove of the engagement member that rotates the control shaft member around the axis. A fuel injection device comprising: an injection timing control member that displaces the control sleeve in the axial direction of the plunger via the injection timing adjustment pin that is engaged with the injection timing adjustment pin.