JP2571877Y2 - Governor of row type fuel injection pump - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed control device for an in-line type fuel injection pump which has improved operation stability in idle operation of an engine.

[0002]

2. Description of the Related Art As disclosed in Japanese Utility Model Laid-Open Publication No. 61-29032, a speed control device for a row type fuel injection pump has a centrifugal weight supported on a cam shaft for driving a plunger of the fuel injection pump. When the centrifugal weight is expanded in response to the rotation speed increase, the shifter extrapolated to the camshaft is pushed, and the tension lever connected to the shifter is rotated against the force of the governing spring, and the tension is pulled. The fuel control rack rod is driven in the fuel decreasing direction via a guide lever supported on the same support shaft as the lever and a floating lever whose fulcrum is displaced by the acceleration lever. The speed control spring composed of a plurality of springs sequentially contacts the movable spring seat in accordance with the amount of rotation of the tension lever, and exerts a drag on the tension lever. Therefore, if the posture of the movable spring seat with respect to the governing spring is abnormal when the governing spring exerts a drag on the tension lever from the idle state, the idle operation of the engine becomes unstable.

FIG. 4 is a perspective view showing a governing device connected to one end of a conventional fuel injection pump without a case. A bracket 35a is connected near the end of the cam shaft 35 of the fuel injection pump, and a pair of centrifugal weights 39 are rotatably supported by a pair of shafts 36 at both ends of the bracket 35a. The upper centrifugal weight 39 is not shown. Centrifugal weight 3
The roller 37 a is supported by the shaft 38 at the end of the ninth arm 37, and is engaged with the front end surface of the shifter 40. The cylindrical shifter 40 is externally slidably supported at the end of the cam shaft 35. An idling spring 42 composed of a plurality of springs is interposed between the rear end 40a of the shifter 40 and the guide cylinder 43 screwed and supported on the case end wall. The initial load of the idling spring 42 is set by adjusting the front and rear positions of the spring seat fitted to the guide cylinder 43 with the adjustment bolt 43b. An intermediate portion of the pull lever 10 is rotatably supported by a support shaft 8 orthogonal to the cam shaft 35 on the case side wall. The forked lower end of the pull lever 10 is connected to the rear end 40 a of the shifter 40 by a pin 41. The bifurcated upper end of the tension lever 10 is moved by a pair of left and right pins 4 to form a movable spring seat 2 described later.
4. A rod 7 substantially parallel to the camshaft 35 is slidably inserted into a block 6 rotatably supported at one end of the pin 4. The front end of the rod 7 is connected to the torque cam 31 by a pin 32. The spring 5 is interposed between the block 6 and the flange formed at the front end of the rod 7.

A lower end 22b of a bifurcated guide lever 22 is rotatably supported by a support shaft 8 supporting the pull lever 10, and is wound around the support shaft 8 and has one end connected to the pull lever 10.
Further, the guide lever 22 is urged to rotate counterclockwise by the spring 9 having the other end locked to the lower end portion 22b, and is brought into contact with the pin 4.

[0005] A spindle 1 rotatably supported on a case top wall.
An acceleration lever 17 operated by an accelerator pedal is connected to the upper end of the lever 8, and the lever 11 is connected to an intermediate portion of the support shaft 18. The support lever 19, which is freely rotatably supported at the lower end of the support shaft 18, is wound around the support shaft 18, and is counteracted by the force of a spring 18 a having one end locked to the lever 11 and the other end locked to the support lever 19. It is urged to rotate clockwise and comes into contact with the protrusion 11 a of the lever 11. An intermediate portion of the horizontal floating lever 21 is rotatably connected to an end of the support lever 19 by a pin 20. Longitudinal grooves are provided at both ends of the floating lever 21, and pins 22a projecting upward from the upper end of the guide lever 22 are engaged with the right grooves. The fuel control rack rod 15 is provided in the left groove of the floating lever 21.
A pin 15b projecting upward from the rear end 15a is engaged. The starting spring 2 is stretched between the rear end 15a of the fuel control rack 15 and the locking member 14 on the end wall of the fuel injection pump.

A pin 16 extending laterally from the fuel control rack rod 15 is engaged with a groove at the upper end of the fuel limiting lever 13. The fuel limiting lever 13 is rotatably supported at its upper end by the pin 12 at the upper end of the bracket 30. The claw 13 a formed at the lower end of the fuel limiting lever 13 is normally engaged with the cam surface 31 a of the torque cam 31. The bracket 30 is rotatably supported at an intermediate portion on a case side wall by a support shaft 28. The peripheral edge of the full load setting lever 27 rotatably supported by the support shaft 28 is engaged with the front end of a bolt 29 supported by a bracket 30 so as to be capable of being screwed and adjusted. Therefore, when the full load setting lever 27 is rotated, the bracket 3
0 tilts, and the front and rear positions of the pin 12 change. The torque cam 31 is rotatably supported on a case side wall by a support shaft 33.

When the engine is started, when the torque cam 31 is turned clockwise by an actuator (not shown) against the force of the spring 5, the claw 13a of the fuel limiting lever 13 can be engaged with the step portion 31b. By turning the acceleration lever 17 to the maximum in the direction of the arrow, the fuel control rack 15 can be operated to the starting fuel increasing position. The above configuration is almost the same as that of the conventional speed control device of the row type fuel injection pump.

As shown in FIG. 5, the governing rod 25 has a rear end (right end in the figure) fixed to a case end wall, and a spring seat 3 connected to a front end of the governing rod 25 and a rear end side. In order to interpose the governing springs 23a and 23b double wound around the governing rod 25 between the movable spring seat 24 and the movable spring seat 24 slidably mounted on the movable spring seat 24, the movable spring seat 24 has a governing spring 23a. And a guide cylinder 24a for partitioning between the end of the spring and the end of the governing spring 23b. The movable spring seat 24 is connected to the pull lever 10 by the pin 4.
To the upper end.

As described above, the governing spring 2 having different winding diameters
In the configuration in which the movable spring seat 24 is not in contact with the governing springs 23a and 23b, the movable spring seat 2
When the cylinder 4 is tilted as shown in FIG. 5, the upper peripheral wall of the end of the guide cylinder 24a comes into contact with the peripheral edge of the governing spring 23b, and the seat surface 24d of the movable spring seat 24 becomes the end of the governing spring 23a, 23b. No longer parallel to the part. In a state where the movable spring seat 24 is inclined,
The timing at which the ends of the governing springs 23a and 23b contact the movable spring seat 24 and the force exerted on the movable spring seat 24 become unstable, and the engine shifts from idle operation to normal operation, or normal operation. The operation (rotational speed) when returning to idle operation from the above becomes unstable.

In other words, as shown by line 51 in FIG.
When the rotation speed of the cam shaft 35 of the fuel injection pump becomes higher than the idle rotation due to the operation of the acceleration lever 17 or the load fluctuation of the engine, the movable spring seat 24 first contacts the speed adjusting spring 23b. When the tension lever 10 rotates against the force of the governing spring 23b, the floating lever 21 is rotated by the guide lever 22 which rotates following the rotation of the tension lever 10, and as shown by the line 52 in FIG. The rack 15 is returned in the fuel decreasing direction.
When the rotation speed of the cam shaft 35 further increases, the movable spring seat 2
4 also hits the governing spring 23a, and the fuel control rack rod 15 is returned in the fuel decreasing direction as shown by the line 53 in FIG. As described above, if the movable spring seat 24 is tilted as shown in FIG. 5, the state of separation and contact with the governing spring 23b changes, and the break point A between the line 51 and the line 52 changes, and fuel control is performed. Rack rod 1
The rotation speed of the fuel injection pump at the break point A of 5 does not take a constant value.

[0011]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the object of the present invention is to move a movable spring seat in a normal posture to and away from a governing spring that regulates rotation of a tension lever, and It is an object of the present invention to provide a speed control device for an in-line fuel injection pump that eliminates unstable operations near idle operation.

[0012]

In order to achieve the above-mentioned object, according to the structure of the present invention, a lower end of a tension lever having an intermediate portion rotatably supported on a case side wall is provided by a centrifugal weight supported by a cam shaft. A cylindrical movable member connected to a shifter pushed along the camshaft by the expanding movement, and an upper end of the pulling lever is externally inserted into a governing rod extending in parallel with the camshaft from a case end wall by a pin. A plurality of regulating springs having different winding diameters are interposed between the movable seat and a spring seat connected to a spring seat and connected to a free end of the regulating rod, and the movable spring seat relative to the regulating rod is provided. Either an equilibrium weight for suppressing tilting of the movable spring seat is provided below the pin, or an axial center of the pin with respect to the movable spring seat is biased toward an end contacting the governing spring. It is characterized by the following.

Further, according to the structure of the present invention, the lower end of the pulling lever having the middle portion rotatably supported on the case side wall is pushed along the cam shaft by the expanding movement of the centrifugal weight supported on the cam shaft. And the upper end of the tension lever is connected by a pin to a cylindrical movable spring seat extrapolated from a case end wall to a speed-adjusting rod extending parallel to the camshaft, and a free end of the speed-adjusting rod is connected. A plurality of governing springs having different winding diameters are interposed between a spring seat coupled to the movable spring seat and an end seating surface of the movable spring seat, and ends of the plurality of governing springs are attached to the movable spring seat. An inner peripheral portion and an outer peripheral portion of the guide cylinder coupled to the seat surface are separated from each other, and the movable spring seat is tilted with respect to the governing rod at an end opposite to the end seat surface of the movable spring seat. The balance weight is provided.

[0014]

According to the present invention, since the balance weight is integrally provided below the movable spring seat slidably inserted into the governing rod, the movable spring seat is always pulled downward, and the movable spring is driven by an external force. Tilt around the seat pin is suppressed. Therefore, even if the tension lever rotates or tilts due to the change in the centrifugal force of the centrifugal weight, the seat surface of the movable spring seat is always kept substantially perpendicular to the winding axis of the governing spring. (It is kept coaxial with the governing rod), and the movement of the governing spring to and from the movable spring seat becomes stable. Therefore, the rotation speed of the fuel injection pump at the time when the governing spring begins to exert a drag on the tilting operation of the tension lever is maintained at a substantially constant value, and a stable idle operation of the engine is obtained.

[0015] Even if a counterweight is integrally formed at the rear portion of the movable spring seat, that is, at the end opposite to the seat surface of the movable spring seat,
The tendency of the seat surface of the movable spring seat to fall forward is suppressed. That is, since the movable spring seat is kept coaxial (substantially horizontal) with the governing rod, the same operation and effect as described above can be obtained. By separating the ends of the plurality of governing springs into an inner peripheral portion and an outer peripheral portion of the guide cylinder coupled to the seat surface of the movable spring seat,
Since the abutment surfaces of the movable spring seats independently contact each other, the ends of the plurality of governing springs do not become entangled with each other, and the operation of separating and connecting the governing springs to the movable spring seat is further stabilized.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 2, according to the present invention, a counterweight 2 is provided below a pin 4 of a cylindrical movable spring seat 24. FIG.
4c is provided. From the seat surface 24d to the movable spring seat 24,
A guide cylinder 24a projecting between the governing springs 23a and 23b having different winding diameters is integrally formed, and a pin 4 extending to both sides from the movable spring seat 24 is rotatably supported by the tension lever 10. Is done. The other configuration is the same as the conventional configuration shown in FIG.

Next, the operation of the speed control device of the fuel injection pump according to the present invention will be described. In FIG. 4, when the acceleration lever 17 is rotated counterclockwise together with the support shaft 18, the support lever 19 is also rotated in the same direction by the force of the spring 18a, and the position of the pin 20 moves forward. I do. Accordingly, the fuel control rack rod 15 is pushed forward (in the fuel increasing direction) via the floating lever 21.

As the amount of fuel increases, the centrifugal weight 39 is expanded, and the shifter 40 is pushed rearward by the roller 37a against the force of the idling spring 42. Accordingly, the tension lever 10 is rotated counterclockwise about the support shaft 8,
The movable spring seat 24 moves forward along the speed adjusting rod 25, and the seat surface 24d comes into contact with the speed adjusting springs 23b and 23a sequentially. The inner diameter of the shaft hole 24b of the movable spring seat 24 is larger than the outer diameter of the governing rod 25, and moves smoothly with the rotation of the tension lever 10.

As shown in FIG. 1, in the present invention, since the counterweight 24c is provided below the pin 4 of the movable spring seat 24, the movable spring seat 24 does not tilt and is substantially in a horizontal posture, that is, The central axis of the shaft hole 24b of the movable spring seat 24 is kept parallel to the speed adjusting rod 25. Seat surface 24
d comes into surface contact with the ends of the governing springs 23a and 23b and does not hit one side. Accordingly, the seat surface 24d is provided with the governing spring 23a,
The change of the spring force applied to the movable spring seat 24 at the time of moving toward and away from the end of 23b becomes very stable (there is no change in the point A in FIG. 6). On the other hand, stable idle operation can be obtained.

In the embodiment shown in FIG. 3, the end of the movable spring seat 24 opposite to the seat surface 24d supporting the spring 23a is extended by a required dimension s, and this extended portion is connected to the balance weight 24e.
It is assumed that. The pins 4 extending from the movable spring seat 24 to both sides are arranged as close as possible to the seat surface 24d.
In other words, in this embodiment, the axial center of the pin 4 with respect to the movable spring seat 24 is
3b is biased toward the end in contact with 3b. Thereby, the seat surface 24d of the movable spring seat 24 as shown in FIG.
Of the vehicle forward (toward the free end of the governing rod) is suppressed.

The construction of this embodiment is easy to machine,
In addition, the shaft hole 24b externally fitted to the governing rod 25 becomes longer,
As a result, the operation of the movable spring seat 24 becomes smooth.

[0022]

As described above, according to the present invention, the lower end of the pulling lever having the intermediate portion rotatably supported on the case side wall is moved along the cam shaft by the expanding movement of the centrifugal weight supported on the cam shaft. An upper end of the pulling lever is connected by a pin to a cylindrical movable spring seat extrapolated from a case end wall to a speed adjusting rod extending in parallel with the camshaft; A plurality of governing springs having different winding diameters are interposed between a spring seat connected to the free end of the movable spring seat and the movable spring seat, and a counterweight that suppresses tilting of the movable spring seat with respect to the governing rod is provided by the movable mass. Since the spring is provided at a position below the pin of the spring seat or at the end opposite to the end seat surface of the movable spring seat that receives the governing spring, the cam is operated in accordance with the operation of the acceleration lever or the load fluctuation of the engine. When the tension lever is rotated by the centrifugal weight of the shaft, The inclination of the movable spring seat is suppressed by the action of the weight, push-pull operations of the movable spring seat and governor spring is smoothly performed. Therefore, there is no variation in the change in the fuel amount due to a load change or the like in the idle operation of the engine, and a stable idle operation of the engine can be obtained.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a main part of a speed control device of a row type fuel injection pump according to a first embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a side sectional view showing a main part of the speed control device of the row type fuel injection pump according to the second embodiment of the present invention.

FIG. 4 is a perspective view of a conventional speed control device for a row-type fuel injection pump.

FIG. 5 is a side cross-sectional view showing a malfunction state of the tuning apparatus.

FIG. 6 is a characteristic diagram of the same-line type fuel injection pump.

[Explanation of symbols]

10: tension lever 23a: regulating spring 23b: regulating spring 24: movable spring seat 24c: balancing weight 24e: balancing weight 25: regulating rod 35: cam shaft 39: centrifugal weight 4
0: Shifter

Claims (2)

(57) [Scope of request for utility model registration] 1. A lower end of a pulling lever having an intermediate portion rotatably supported on a side wall of a case is connected to a shifter which is pushed along the camshaft by an expanding movement of a centrifugal weight supported by a camshaft. A spring seat connected to a cylindrical movable spring seat externally inserted into a governing rod extending from the end wall of the case in parallel with the camshaft by a pin, and an upper end of the pulling lever connected to a free end of the governing rod; A plurality of governing springs having different winding diameters are interposed between the movable spring seat and the movable spring seat, and a balance weight for suppressing the tilt of the movable spring seat with respect to the governing rod is provided below the pin of the movable spring seat. A speed control device for an in-line fuel injection pump, comprising: 2. A lower end of a pulling lever having an intermediate portion rotatably supported on a side wall of a case and connected to a shifter which is pushed along the camshaft by an expanding movement of a centrifugal weight supported by a camshaft. A spring seat connected to a cylindrical movable spring seat externally inserted into a governing rod extending from the end wall of the case in parallel with the camshaft by a pin, and an upper end of the pulling lever connected to a free end of the governing rod; A plurality of governing springs having different winding diameters are interposed between the movable spring seat and an end seat surface of the movable spring seat, and ends of the plurality of governing springs are coupled to the seat surface of the movable spring seat. An equilibrium weight is provided at an end opposite to the end seat surface of the movable spring seat, which is separated from an inner peripheral side portion and an outer peripheral side portion of the guide cylinder, and suppresses tilting of the movable spring seat with respect to the governing rod. A speed control device for an in-line fuel injection pump.