JPH053721Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a governor for a fuel injection device for a diesel engine, and particularly to a governor with a hydraulic servo.

(Prior technology) This is the fourth hydraulic servo governor of this type.
There is something like the one shown in the figure.

That is, in the figure, a is a control rack, c is a piston, and b is a punch connecting control rack a and piston c. d is a hydraulic servo piston, and e is a cylinder in which the piston c slides. g is an oil inflow path provided in cylinder e, and k is an oil outflow path. f is a spool valve, which consists of a large-diameter spool _f1 that slides in the hole of the piston, a small-diameter connecting punch part _f2 , and a large-diameter spool _f3 , and there are oil flow paths _h1 , _h2 in the piston. ,h ₃
is formed. As shown in the figure, the hydraulic servo piston device has a cylinder divided into two chambers A and B by a large diameter portion _c2 at the center of the piston. 1 is a stop solenoid which can be appropriately connected to the tip of a lever p via a bifurcated punch m. n is start spilling. p ₁ , p ₂ , p ₃ indicate each pivot point. s is the main spring, t is the fly weight, r is the full load stopper, u is the connecting punch, and v is the control lever, which utilizes the balance between the centrifugal force of the rotating fly weight t and the force of the main spring s. This controls the engine speed.

(Problems to be Solved by the Invention) In the prior art described above, the oil flowing into the chamber A via the passage g provided in the cylinder e of the hydraulic servo piston device d passes through the oil passages h ₁ and h ₂ . The oil then flows out from the oil outlet k.

When the control lever v is moved in the direction of arrow 1, the main spring s moves in the opposite direction and pushes the lever p, which moves the spool valve f to the left and moves the control rack a in the direction of increasing fuel via the piston c and connecting punch b. move to. At this time, the spool _f3 of the spool valve moves to the left in the figure to close the oil outlet k. Therefore, the oil entering chamber A of the servo piston device flows into chamber B through oil passages h ₁ , h ₂ , and h ₃ , and the piston is affected by the difference in the areas receiving hydraulic pressure between chambers B and A. Since c is moved to the left, the oil outlet k will open again. In this way, these hydraulic servomechanisms simply follow the movement of spool _f3 and move in the same direction, maintaining the original state. Therefore, with this type of hydraulic governor, position control is easy. is not affected by changes in supply oil pressure.

In other words, the hydraulic servo piston device only works as a means to double the hydraulic pressure, and since the easy position control is not affected by changes in the hydraulic pressure as described above, when the engine is to be stopped, the supply of Even if the oil is drained, the purpose is not achieved and the spool must be moved to the stop side using the link mechanism.

That is, in the figure, the stop solenoid l must be energized to move the two-pronged punch m, and the spool valve f must be moved to the stop side so that it comes into contact with the tip of the lever p and overcomes the force of the start spring n. Problems such as the use of a complicated ring mechanism and the need for a solenoid that can generate a large amount of force to overcome the force of the start spring require a large amount of force for the engine stop mechanism. It is something that you have. Similarly, the boost compensator requires a large amount of force, and the characteristics of the boost compensator are affected by the position of the control lever and the engine speed.

Another problem is that since the start spring n works against the friction of each link, it is desirable to have as large a setting force as possible, but if it is too large, it will affect idle control.
A very weak spring constant is required. Considering that the start spring n needs to extend by the same amount as the stroke of the control rack a, the spring design has little freedom and is extremely difficult.

On the other hand, in this type of governor, the regulation of the engine speed is determined by the thrust of the fly belt t, the spring constant of the main spring s, the link ratio of the lever p, and the like.

Therefore, the regulation starting rotational speed must be adjusted by compressing the main spring s using the control lever v and changing the setting force. Therefore, when trying to reduce the regulation in the high-speed range with generator specifications, etc., the spring constant of the main spring s must be made relatively small, and as a result, the control lever can be adjusted from idling rotation speed to rated rotation speed. There is a problem that the operating angle of v becomes large, making it almost impossible to implement.

(Means and operations for solving the problems) This invention was devised in view of the various problems mentioned above, and is intended to control a spool valve having flanged spools at both ends in a governor with a hydraulic servo mechanism. A start spring is interposed between the spool on the easy side and the piston, and the flange of the spool on the opposite side is brought into contact with a lever operated via a main spring device that is extended and contracted by a control lever. The structure of the above-mentioned main spring device is formed by a main spring which is prevented from elongating to a certain extent by a stopper, and an idle spring provided between the stopper and the lever, and the stroke of the start spring is controlled by the control rack. Since it can be made smaller regardless of the stroke, increasing the spring constant will not affect the idle characteristics, making spring design easier, and the force required to stop the engine or boost compensator can be achieved by simply compressing the start spring. It requires only a small amount of force, and the main spring can be stopped to prevent it from elongating beyond a certain point.
It is possible to control idling and high-speed rotational speed with a small control lever angle.

(Example) An embodiment of this invention will be described based on the drawings.

In Fig. 1, 1 is a control rack, 2 is a pestle that connects the piston 3 and the control rack 1, and 4 is a hydraulic servo piston device with a cylinder 4 ₁
and a piston 3. The piston 3 has a large diameter part 3 ₂ almost at the center, and the cylinder chamber is called A ₁ .
It is divided into 3 parts _{3 1 and} 3 ₃ , which are smaller in diameter than 3 ₂ , on both sides. A hole passes through the center of the piston 3, and a spool valve 5 as shown in the drawing is inserted into this hole.
As shown in the figure, this spool valve has spool portions 5 ₁ and 5 ₃ which are flanged at both ends, and these are connected by a small-diameter continuous punch portion 5 ₂ . A start spring 6 is interposed between the end surface of the piston portion 3 ₁ and the collar-shaped spool portion 5 ₁ .
Reference numerals 7, 8, and 9 indicate oil flow paths, and reference numerals 10 and 11 indicate an oil inlet and an oil outlet. 12 is a stop solenoid or boost compensator, and 13 is a bifurcated punch, one end of which can be appropriately connected to the spool portion ₅₃ of the spool valve. 14 is a lever, 14
₂ is a pivot point, 15 is a main spring, 16 is a fly weight, and 18 is a control lever.

One important point in the above embodiment of this device is that the start spring 6 is interposed between the flanged spool portion 5 ₁ of the spool valve 5 and the end of the cylindrical portion 3 ₁ of the piston 3 as described above. It is a characteristic. In other words, the oil that has flowed into chamber _A1 via the oil inlet is passed through passage 7,
Pass through 8 and 9 and enter Room _B1 . The piston moves to the left due to the difference in area between chamber A ₁ and chamber B ₁ . Therefore, due to the action of hydraulic pressure, the stroke of the start spring can be made smaller regardless of the stroke of the control rack, and even if the spring constant is increased, it will not affect the idle characteristics, making spring design easier. . Also, as mentioned above, when the spool valve 5 is free, the piston 3 always tries to move to the left, that is, to the full side, so the contact point between the lever 14 and the spool valve 5 is of the type that is pressed to one side as shown in the figure. In addition, there is no need for contacts that require precision, such as conventional pin contacts (FIG. 4) or sliding contacts.

Further, the force required to stop the engine is sufficient to compress the start spring 6 in the opposite direction to that described above, and since the stroke of the start spring 6 is small, a small force is required.

Further, FIG. 2 is a specific example showing an enlarged view of the main spring device shown in section P in FIG. Attach the stopper 20 to the main spring 15 and connect the stopper 20 and the flanged fitting _21.
In addition, an idle spring 19 is provided between the attachment 22 of the lever 14 related to the spool valve 5 and the collar-shaped attachment 21 ₁ of the main spring, and this point is also devised. This is one of the main characteristics of By providing the stopper 20 to prevent the main spring 15 from elongating to a certain extent as described above, it is possible to control the undoing and the rotational speed used in the high speed range with a small control lever operating angle.

That is, as shown in FIG. 3a, in the idling range, the main spring 15 hits the stopper 20 and becomes a kind of rigid body, and the thrust of the idle spring 19 and the flyweight 16 are balanced, and in the normal use range, as shown in FIG. As shown in b, the idle spring 19 is in close contact with the main spring force and the idle spring contact force are in balance with the flyweight thrust force. Therefore, the relationship between the control lever operation angle and the engine speed is as shown in line a in Figure 3c, and by applying a stopper to prevent the main spring from elongating to a certain extent, the engine can be idled at a small control lever angle. It is possible to control the rotational speed used in the high-speed range. Note that line b shows the prior art.

(Effect of the invention) This invention is constructed as detailed above, so
In other words, by interposing the start spring between the spool valve and the piston, the stroke of the start spring can be made small regardless of the stroke of the control rack, so even if the spring constant is increased, the idle characteristics will not be affected. , thus making the design of the spring easier. In addition, when the spool valve is free, the piston always tries to increase the fuel in the control rack, so the lever and spool valve may be of the type that is pressed to one side, and the type that requires precision such as a pin contact or a sliding contact is sufficient. There is no need to use contacts. Furthermore, the force required to stop the engine and boost compensator is as small as compressing the start spring, and the characteristics of the boost compensator have the advantage of not being affected by the control lever position or engine speed.

In particular, since a stopper is applied to prevent the main spring from elongating beyond a certain degree, it is possible to control idling and rotational speed in the high-speed range with a small control lever operation angle.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram illustrating the main parts of this invention; Fig. 2 is an enlarged view of section P in Fig. 1; and Fig. 3 is a schematic diagram of a preferred embodiment of the main spring device. a, b, and c are explanatory diagrams regarding the relationship between the control lever operation angle and the engine rotation speed when the control lever shown in FIG. 2 is used; FIG. 4 is a schematic diagram of a conventional device. 1... Control rack, 2... Connecting punch, 3
... Piston, 4 ... Hydraulic servo piston device,
5... Spool valve, 5 ₁ , 5 ₃ ... Spool, 6...
...Start spring, 14...Lever, 15...
...Main spring, 18...Control lever, 19...Idle spring, 20...Stopper, 21...Stopper.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a governor with a hydraulic servo mechanism, a spool valve is inserted into the piston of the hydraulic servo piston device, and the spool valve has a flange-shaped spool at both ends. A start spring is interposed between the spool on one side and the piston, and the flange of the spool on the opposite side can be brought into contact with a lever operated by a control lever via a main spring device. A fuel injection system for diesel engines. (2) The above main spring device consists of a main spring that is prevented from elongating to a certain extent by providing a stopper on the stopper of the main spring, and an idle spring that is provided between the stopper and the lever. A fuel injection device for a diesel engine according to claim 1, characterized in that the fuel injection device comprises: