JPH0528347Y2 - - 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 second 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 rod 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 inside the piston hole, a small-diameter connecting rod part _f2 , and a large-diameter spool _f3 , and the 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 connected to the tip of a lever p via a bifurcated connecting rod m. n is a start spring. 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 rod, 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, 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 . Then, the oil 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 rod p, which moves f to the left and piston c,
Control rack a is moved in the direction of increasing fuel via connecting rod b. At this time, the spool of the spool valve
f ₃ moves to the left in the figure to close the oil outlet k. Therefore, the oil entering the chamber A of the servo piston device is in the oil path.
The oil flows into chamber B through h ₁ , h ₂ , and h ₃ and moves the piston c to the left due to the difference in the areas receiving the oil pressure in chambers B and A, so the oil outlet k opens again. It turns out. 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 bifurcated rod 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 link 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 has the following.

(Means and effects for solving the problem) This invention was made in view of the above problem, and is a governor with a hydraulic servo mechanism, in which the central part is large so as to divide the cylinder into two hydraulic chambers. A piston of a hydraulic servo piston device is formed by a portion having a diameter, a portion having flanged end portions on both sides having a smaller diameter than the portion, and a portion having a smaller diameter, and the piston portion having the flanged end portion is stepped. A sleeve is fitted around the small diameter portion of the piston, the sleeve and the control rack are connected by a connecting rod, and a stop spring is inserted between the sleeve and the flanged end of the piston. When inserted, the stop spring is compressed by the pressure oil flowing into one chamber from the oil inflow path, and the sleeve is pushed to the left and fixed to the stepped contact surface of the brim-shaped end, so that it functions as a normal hydraulic piston. The sleeve that cuts off the supplied hydraulic pressure is moved by a stop spring in the opposite direction, ie, to the right, to move the control rack in the direction of fuel reduction and to easily and accurately stop the energy.

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

In FIG. 1, 1 is a control rack, 2 is a rod connecting the sleeve 3 and the control rack 1, and 6 is a hydraulic servo piston device having a cylinder 7 and a piston 4. The piston has a large-diameter portion 4 ₂ approximately at the center that divides the cylinder into chambers A ₁ and B ₁ , and on both sides there is a portion 4 ₁ with flanged ends with a smaller diameter than 4 ₂ and a small-diameter portion 4 ₃ It's getting more and more familiar. The piston portion ₄₁ is formed into a stepped shape as shown in the figure, and the sleeve 3 is fitted around the smallest diameter portion ₄₄ , so that the brim-shaped end of the sleeve 3 forms a stepped joint between the piston portions _{41 and 41} . It is designed so that it can be joined to surface 4 ₅ . Reference numeral 5 designates a stop spring fitted between the collar portion of the piston portion ₄₁ and the sleeve 3. 8 is an oil inlet formed in the cylinder 7;
16 is the end of the piston small diameter portion 4 ₃ and the spool 1
2 This is the oil outlet that opens at ₃ . 12
is a spool valve, which consists of a large diameter spool portion 12 ₁ that slides inside the piston hole, a small diameter connecting rod portion 12 ₂ and a large diameter spool portion 12 ₃ , and there are oil flow paths 9, 10, 11 is formed. 14 is a start spring, and 15 is a lever.

In the above embodiment, the point of the hydraulic servo mechanism, that is, the end surface of the sleeve 3 fitted to the piston 4 of the hydraulic servo piston device 6 is connected to the stepped portion 4 ₅ of the piston.
An important feature is the structure in which a stop spring 5 is interposed between the piston ₄₁ and the sleeve 3, which are brought into contact with each other.

Now in normal use condition, the cylinder chamber is opened from the oil inlet passage 8.
When hydraulic pressure is applied due to the oil flowing into A ₁ , the stop spring 5 is compressed by the hydraulic pressure, and the sleeve 3 is pushed toward the left end so that the stepped contact surface of the flanged piston 4 ₁ (Stepped portion) ₄ Since it is fixed to the piston 4 by contacting the 5, it functions as a normal hydraulic servo piston and works without being affected by the supplied hydraulic pressure, which is the same as described in relation to the prior art. be. Next, when stopping the engine, the supplied hydraulic pressure is cut, and as a result, the sleeve 3 is moved to the right by the stop spring 5, regardless of the piston position, and as a result, the connecting rod 2
The control rack 1 moves in the direction of decreasing fuel, and the engine stops with no injection.

Therefore, in the embodiment of this invention, conventionally, when stopping the engine, it was not enough to just cut off the supply oil pressure, and it was necessary to use a complicated link mechanism to move the spool to the stop side. By adding a simple mechanism to the hydraulic servo piston device, the engine can be stopped easily.

Note that if the oil pressure supplied to the hydraulic servo mechanism is taken from the discharge pressure of the oil pump and used as engine lubricating oil pressure, it can also be used as a reverse rotation prevention device or a protection device when oil pressure drops.

(Effects of the invention) Since this invention is constructed as described above, it works as a hydraulic servo piston without being affected by fluctuations in the supplied hydraulic pressure during normal use, and when the engine is stopped, the supplied hydraulic pressure is cut off. Simply, regardless of the piston arrangement, the sleeve is moved in the opposite direction by the stop spring, moving the control rack in the direction of fuel reduction, resulting in no injection, and the engine can be stopped easily and accurately. Therefore, it is possible to eliminate the need to move the spool to the stop side using a complicated link mechanism as in the past, and there is no need to use a solenoid that can generate a large force to overcome the force of the main spring. It has merits.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating the main parts of this invention, and FIG. 2 is a schematic diagram of a conventional device. 1... Control rack, 2... Connecting rod, 3
... Sleeve, 4 ... Piston, 4 ₁ ... Piston part, 4 ₂ ... Piston part, 4 ₃ ... Piston part, 4 ₄ ... Piston part, 4 ₅ ... Stepped contact surface, 5 ... Stop spring, 6... Hydraulic servo piston device, 7... Cylinder.

Claims (1)

[Scope of utility model registration request] A portion 4 ₂ having _a large diameter at the center to divide the cylinder 7 into hydraulic chambers A ₁ and B ₁ , and a portion 4 1 having flanged end portions having a smaller diameter than the portion 4 ₂ on both sides; The small diameter portion 4 ₃ forms the piston 4 of the hydraulic servo piston device 6 , and the piston portion 4 ₁ is formed in a step shape, and the sleeve 3 is fitted around the small diameter portion 4 ₄ . The sleeve 3 and the control rack 1 are connected by a connecting rod 2, and a stop spring 5 is inserted between the sleeve 3 and the flanged end ₄₁ of the piston.
The pressure oil flowing into A ₁ compresses the stop spring 5 and pushes the sleeve 3 to the left side at the flanged end 4 ₁
The sleeve 3 is fixed to the stepped contact surface ₄₅ of the sleeve 3 to function as a normal hydraulic piston, and when the supplied hydraulic pressure is cut off, the sleeve 3 is moved to the right by the stop spring 5, and the control rack 1 is moved in the direction of fuel reduction. A fuel injection device for diesel engines, which is characterized by: