JPS593163A - Fuel injection pump - Google Patents

Abstract

PURPOSE:To obtain a compact and light-weight fuel injection pump, by arranging a plurality of plunger pumps radially about one rotary shaft so that the plungers of the plunger pumps are sequentially operated by a single cam. CONSTITUTION:A plurality, for example four, of plunger pumps 4 are equiangularly spaced with respect to a casing 2, around a cam drive shaft 3 associatingly rotated by an engine. Each plunger pump 4 which is incorporated therein with a plunger 14 fitted in a sleeve 13 and a control pinion 15, is so arranged that fuel is pumped out when it is moved in the direction A after it closes a suction and discharge port 18, and the above-mentioned pumping is ceased when a notch groove 14a formed in the outer peripheral surface of the plunger 14 is communicated with the suction and discharge port 18. Such a reciprocating motion of the plunger 14 is carried out by a cam 25 through a peripherally displaceable timing control sleeve 6 which is operated by an actuator 22 through a lever 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection pump for a diesel engine, and in particular to a fuel injection pump that has a simplified and compact structure by arranging a plurality of plunger pumps radially around one rotating shaft. Regarding injection pumps.

Conventionally, in-line fuel injection pumps used in diesel engines have as many pump units as the number of cylinders in the engine arranged in a straight line. A cabana is required. For this reason, the structure was complicated, large, and heavy, resulting in high cost. In addition, the recently used distribution type fuel injection pumps have the disadvantage that they cannot inject a large amount of fuel because the fuel that is pumped from one pump unit is distributed to each cylinder by a distributor. was there.

The present invention has been made to eliminate the drawbacks of the prior art described above.
The purpose of this invention is to provide a compact and lightweight fuel injection pump by arranging a plurality of plunger pumps 17 radially around one rotating shaft.

! Another purpose is to enable fuel injection with a simple structure by pressing the nfC plunger attached to each of a plurality of plunger pumps to the injection amount with the cam surface of a single cam body. . ! Another purpose is to enable adjustment of fuel injection timing with a simple structure by rotating a timing control sleeve equipped with a tappet that engages with the cam surface of the cam body and presses the plunger. It is. Still another object is that the fuel injection amount can be adjusted with a simple structure by rotating a control pinion that is attached to each of a plurality of plunger pumps and integrally rotates one NFC plunger with a single control gear. It is to do so.

In short, the present invention includes a short cylindrical frame, a cam drive shaft supported at the axial center of the frame with limited axial movement, and a cam drive shaft that rotates in conjunction with the rotation of an engine. a sleeve arranged radially around the frame with the moving shaft as the center; a sleeve fixed to the frame; and a plunger integrally fitted with a control pinion that is slidably inserted into the axial center of the sleeve; a plunger pump each comprising a flfc cam body fixed to the cam drive shaft, and the cam,
a timing control sleeve fitted into the drive shaft; and a tappet slidably fitted into the timing control sleeve and arranged so as to face the plunger of the plunger pump and the cam surface of the cam body, respectively. and a control gear that is fitted into the cam and the drive shaft and meshes with the control pinion and rotates in conjunction with the operation of the fuel injection amount adjusting device.

The present invention will be described and explained below based on embodiments shown in the drawings. A fuel injection pump 1 according to the present invention includes a frame body 2, a cam drive shaft 3, a plunger pump 4, a cam body 5, a timing control sleeve 6, a tappet 7, and a control gear 8. The frame body 2 is fixed to the engine body 11 and has a first and short cylindrical shape. ing.

The cam drive shaft 3 is rotatably supported at the axial center of the frame body 2 by a bearing 12 having a structure capable of withstanding thrust loads, and is rotatably supported by an engine (not shown). It rotates with a delay in rotation.

A plurality of plunger pumps 4 are mounted radially on the frame 2 around the cam drive shaft 3, four in this embodiment at the same intervals. Insert and secure into hole 2a -nfC sleeve 1
3, and an f1fc hollow hole 13 formed in the axial center of the sleeve.
11.7' (includes a plunger 14 and a control pinion 15).A notch groove 14a is formed diagonally on the outer circumferential surface of the plunger 14.A shaft portion 14b of the plunger formed axially opposite to f
The collar portion 15a of the control pinion 15 is fitted into the two s portions t4c of 'L'fC, so that the control pinion rotates integrally with the plunger 14. In Fig. 2, 18 is a fuel intake/discharge port;
9 is an injection pipe.

Then, the plunger 14 moves in the direction of arrow A in FIG.
4 moves in the direction of arrow A, and when the notched groove 14a meets the fuel intake/discharge port 18, the fuel flows back into the fuel reservoir (not shown), and the pressure feeding of the fuel ends.

The cam body 5 is formed into a disk shape and is fixed to the cam drive shaft 3. The timing control sleeve 6 is fitted onto the cam drive shaft 3, and has a collar portion 6al formed on the timing control sleeve.
d, it is arranged between the plunger 14 and the cam body 5. A timing control lever 21 is fixed to the timing control sleeve, and the timing control lever is fixed to the frame body 2 and fitted into the forked portion 23a of the actuator 23 of the detector 22. Then, when the detector 22 detects the engine speed, load, temperature, etc. and operates, the actuators 1 to 23 move, and the timing control IJ =
It is designed so that it can be rotated by a certain angle via a flow U timing control lever 21.

The tappets 7 are slidably inserted into four holes 6b formed in the threaded portion 6a of the timing control sleeve 8 so as to be able to face the plungers 14 of the plunger pump 4, respectively. , rollers 25 and 26 are pivotally mounted on both ends of the tappet.

The roller 25 is arranged between the roller 25 and the plunger 14 so that it can come into contact with the cam surface 5a of the cam body 5, and the four spring supports can come into contact with the body 27. The settings are as follows. The body of the spring holder is a compression spring 2.
As shown in FIG. 2, it is energized in the direction of arrow B by C1W and 8, so that the lower end of the plunger 14 can come into contact with it.

The control gear 8 is the cam drive shaft 7) 3 [f &
, and are attached to each of the four plungers 14 f'
Lf? : It is designed to mesh with the control pinion 15. The control gear is connected to a fuel injection control device, such as a governor 29 that operates in conjunction with the operation of an accelerator pedal in a car. 8
It is designed to rotate.

The present invention is constructed as described above, and the operation of (v) below will be explained. When the cam drive shaft 3 rotates in conjunction with one revolution of the engine and the cam body 5 rotates, the tappet 7 and the spring receiver are moved through the body 27 by the cam surface 5a of the cam body every time the cam body rotates. NTC arranged in injection order
The plunger 14 of the plunger pump 4 is successively pushed in the direction of arrow A, against the spring pressure of the compression spring 28, as shown in FIG. Then, the compressed and high-pressure fuel passes through the injection pipe 19 and enters the injection nozzle (
71. VC is injected from the combustion chamber (not shown) of the engine (not shown). Ru.

In this way, the four plunger pumps 4, which are arranged radially around the cam drive shaft 3 minutes on the frame body 2, inject high-pressure fuel in the injection order every 501 rotations of the cam body. Since a plurality of plunger pumps 4 can be operated by the cam body 5, the fuel injection pump 1 has a simple structure, and is small and lightweight.

In this case, the load applied to the cam surface 5a of the cam body 5 will be quite heavy, but if a material with high wear resistance, such as a tip made of cemented carbide, is used, the durability will be sufficiently increased. The number of round plunger pumps 4 is not limited to four, and more can be attached to the frame body 2, and a tappet 7 may be provided in the first place to provide a tappet 7'L. The tappet also has rollers 25 and 26 pivoted at both ends, but -
The roller 26 may be separated and the kJ'nei may be loaded onto the body 27.

In Fig. 2, for example, when looking at the rotation direction of the cam drive shaft 30 from the right side, when looking at the clockwise direction (counterclockwise direction in Fig. 1) and -4-, the engine speed increases and the plunger pump 4 injection 0 (If you want to advance the 10th stage, the detector 22 detects the engine rotation speed, operates the 1 actuator 23, and the timing control sleeve 6 rotates in the direction of the arrow via the timing control lever 27. By this 1, the cam surface 5 of the cam body 5
If the engagement between the tappet a and the roller 25 of the tappet 7 is quick, the injection timing of the plunger pump 4 can be determined.

Conversely, the engine speed becomes low and the plunger pump 4
When it is desired to delay the injection timing, the timing control sleeve 6 is rotated in the direction of arrow E. In this embodiment, the firing timing is adjusted according to the engine rotation speed7, but the combination of a microcomputer and an actuator can control the engine load or engine speed in addition to the rotation V of the timing control lever 21. It is also possible to select the optimum injection timing for the engine condition by operating υ according to the cooling water temperature, oil temperature, etc.

In this way, the timing control sleeve 6 in which the four tappets 7, which are disposed so as to be opposed to each other on the plunger 14 of the plunger pump 4 and the cam surface 5a of the cam body 5, are slidably inserted is inserted into the timing control sleeve 6, which is disposed so as to be opposed to the plunger 14 of the plunger pump 4 and the cam surface 5a of the cam body 5. Since the injection timing of the fuel injection pump 1 can be adjusted by rotating it according to the number, etc., there is no need for a large and complicated timer as in the past.

Next, the adjustment of the fuel injection amount will be explained. For example, when the accelerator pedal is operated, the governor 29 is activated, the governor detects the engine speed, and the control gear 8 is rotated appropriately. Then, the four control pinions 15 rotate appropriately at the same time, the plunger 14 rotates, and the position of the 17"/414 notch groove 14a relative to the fuel intake/discharge port 18 moves [7, thereby adjusting the fuel injection amount. be able to.

In this way, the fuel injection amount can be adjusted by rotating the control gear 8 and rotating the plunger 14 via the control pinion 15. However, there is no need for a control rack that requires a considerable amount of space, and the entire device is shaped like a thin disk, making it even more compact.

Since the present invention is constructed and operates as described above, the multi-Cr plunger pumps are arranged radially around one rotating shaft, so that a small and lightweight fuel injection pump can be realized. There are effects that can be obtained. -1:
Attached to each of a plurality of plunger pumps fL f (Injection amount K % Et
Since it is possible to perform E, there is an advantage that fuel can be injected with a compact structure.

In addition, by rotating the timing control sleeve equipped with a tappet that engages with the cam surface of the cam body and suppresses the plunger 7c, it is possible to easily perform the M section of the fuel injection timing. . In addition, the plunger attached to each of the plurality of plunger pumps is integrally attached to the plunger. Since the control binions can be rotated at the same time with one control gear, the fuel injection amount can be adjusted with a simple structure, which has significantly superior effects compared to conventional fuel injection pumps. will get it.

[Brief explanation of drawings]

The drawings relate to embodiments of the present invention, and FIG. 1 is a front view of the fuel injection pump, FIG.
The figure is a partially sectional front view showing the mutual relationship between the plunger pump, the cam body, and the tappet. 1 is a fuel injection pump, 2 is a frame body, 3 is a cam drive shaft, 4 is a plunger pump, 5 pieces of cam body, 6 pieces of timing control sleeve, 7 is a tappet, 8 is a control a-
Lugya, 13Fi sleeve, 14#J Nibrangiya, 1
5 is a control pinion, and 29 is a governor for one fuel load (one example of a release adjustment device). Patent applicant: Hino Motors Co., Ltd. Representative, Patent Attorney, FB Kazuo Figure 2, Figure 3

Claims (1)

[Claims] A short cylindrical frame body, a cam drive shaft that is supported at the axial center of the frame with limited axial movement and rotates in conjunction with the rotation of the engine, and a cam drive shaft that rotates in conjunction with the rotation of the engine. A sleeve is arranged radially around the frame and is fixed to the frame, and a plunger is slidably inserted into the axial center of the sleeve and has a control pinion integrally attached thereto. a plunger pump, a cam body f'L* fixed to the cam drive shaft, and f'L* cam body fitted to the cam drive shaft;
a timing control sleeve, a tappet slidably fitted into the timing control sleeve and arranged so as to face the plunger of the plunger pump and the cam surface of the cam body, respectively; and a tappet on the cam drive shaft. A fuel injection pump comprising: a control gear that is fitted and meshed with the control pinion and rotates in conjunction with the operation of the fuel injection amount adjusting device.