JP4567188B2 - Hydraulic clearance adjuster with compression release brake - Google Patents

Description

[0001]
(Cross-reference of related patent applications)
The present invention relates to prior patent application 60/080606 filed on April 3, 1998 and claims the priority of the patent application.
[0002]
(Field of Invention)
The present invention relates generally to a hydraulic clearance adjustment assembly for use in a diesel engine having a compression force release speed reducer. In particular, the present invention relates to a system in which an engine eliminates an undesirable gap by a hydraulic clearance adjusting device during positive power operation, and disables the hydraulic clearance adjustment device during operation by a compression force releasing type reduction gear.
[0003]
(Background of the Invention)
Today, the use of hydraulic clearance regulators in heavy-duty diesel engines has not been realized or at best limited. However, due to technological advances and research on camless hydraulic overhead engines and pneumatic equipment with hydromechanical valve controls, hydraulic clearance adjusters are standard before any other feature of interest. It is thought that it becomes the equipment. Today, in most gasoline vehicles on the road, the hydraulic clearance adjustment device is a standard component and is reliable for the industry. Even if a hydraulic clearance adjuster is used on the exhaust rocker arm of an engine equipped with an engine brake, it will not operate. The constant oil flow to the hydraulic clearance adjuster will cause the hydraulic clearance adjuster plunger to protrude outward from the assembly during braking and the valve will not adhere to the seat at the end of the engine cycle Create a state. A commonly used device added to heavy duty diesel engines is the compression force release speed reducer. This device operates one or more exhaust valves in the operating mode.
[0004]
(Object of invention)
An object of the present invention is to provide a hydraulic clearance adjusting device in a diesel engine having a compressive force releasing speed reducing device.
[0005]
Another object of the present invention is to provide a diesel engine with a hydraulic clearance adjustment device to eliminate undesirable clearances during positive power operation.
[0006]
Another object of the present invention is to provide a diesel engine with a hydraulic clearance adjustment device that can be disabled during a compression force release deceleration operation.
[0007]
Another object of the present invention is to equip the engine with a hydraulic clearance adjustment device to allow the valve timing to be changed during positive power operation.
[0008]
Another object of the present invention is to equip the engine with a hydraulic clearance adjustment device in order to allow the valve lift to be changed during positive power operation.
[0009]
Another object of the present invention is to provide a diesel engine with a hydraulic clearance adjuster to improve exhaust emissions during positive power operation.
[0010]
(Summary of Invention)
The present invention relates to a system used for a diesel engine equipped with a compression force release type reduction gear. The system includes a hydraulic clearance adjustment device disposed on at least one of the intake rocker arm and the exhaust rocker arm. The rocker arm is pivotally attached to the rocker shaft. The rocker shaft includes respective passages for the intake rocker arm and the exhaust rocker arm for supplying a working fluid for actuating the hydraulic clearance adjustment device of the intake rocker arm and the exhaust rocker arm. A control assembly is provided to control the operation of the solenoid valve. This control assembly controls the solenoid valve to operate the adjustment device during positive power operation and to de-energize the adjustment device during compression force release deceleration operation. In addition, activation of the control assembly activates the regulator to adjust valve timing during positive power operation.
[0011]
The system also includes a brake rocker arm assembly having its own cam projection or normal engine brake to facilitate engine braking.
[0012]
The present invention relates to an improved assembly for operating at least one exhaust valve and at least one intake valve of an engine cylinder. The assembly includes a rocker shaft, an intake rocker arm pivotally attached to the rocker shaft for actuating at least one intake valve of the engine cylinder, and at least one exhaust valve of the engine cylinder. And an exhaust rocker arm pivotally attached to the rocker shaft for actuation. The improved assembly includes a clearance adjustment assembly that adjusts a clearance between at least one intake rocker arm and at least one intake valve and between an exhaust rocker arm and at least one exhaust valve. The improvement further includes an energy supply assembly that supplies energy to the gap adjustment assembly to operate the gap adjustment assembly. The improved assembly further includes a control assembly that controls operation of the supply assembly in response to predetermined engine operating conditions.
[0013]
The clearance adjustment assembly may be disposed on the intake rocker arm such that the clearance adjustment assembly adjusts the clearance between the intake rocker arm and the at least one intake valve. The clearance adjustment assembly may be disposed on the exhaust rocker arm such that the clearance adjustment assembly adjusts the clearance between the exhaust rocker arm and the at least one exhaust valve. Finally, the improved assembly includes a pair of gaps to adjust the gap between the exhaust rocker arm and the at least one exhaust valve and between the intake rocker arm and the at least one intake valve. Includes an adjustment assembly.
[0014]
In order to operate the clearance adjustment assembly, the energy supply assembly supplies a working fluid to the clearance adjustment assembly. The energy supply assembly includes a fluid passage for supplying a working fluid to the gap adjustment assembly and an assembly for controlling the flow of the working fluid in the fluid passage. The energy supply assembly is disposed on the rocker shaft.
[0015]
The control assembly operates the supply means to supply energy to the gap adjustment assembly during positive power operation. The control assembly operates the supply means to de-energize the clearance adjustment assembly during engine braking operation. The control assembly operates the supply assembly to de-energize the clearance adjustment assembly after the control assembly detects a predetermined engine operating condition. The control assembly can actuate the supply assembly to actuate the clearance adjustment assembly to improve valve timing of the at least one exhaust valve and the at least one intake valve. Further, the control assembly can actuate the supply assembly to actuate the clearance adjustment assembly to improve the valve lift of at least one of the at least one exhaust valve and the at least one intake valve. Furthermore, the control assembly can actuate the supply means to actuate the clearance adjustment assembly to improve the overlap of the at least one exhaust valve and the at least one intake valve.
[0016]
The present invention will be described with reference to the drawings. In the drawings, the same reference numerals indicate the same members.
[0017]
Detailed Description of the Preferred Embodiment
FIG. 1 shows a rocker arm assembly 10 used in at least one cylinder of a diesel engine. One rocker arm assembly 10 is shown for illustration only. It should be understood that a separate rocker arm assembly 10 is provided for operating at least one exhaust valve and at least one intake valve assembled to the cylinder. The rocker arm assembly 10 includes a pivoting rocker arm 100 that is pivotally attached to a rocker shaft 200. The rocker arm assembly 10 further includes a hydraulic clearance adjustment device 300 attached to the rocker arm 100. The rocker arm assembly 10 further includes at least one valve 400 that controls the operation of the hydraulic clearance adjustment device 300. The operation of valve 400 is controlled by control assembly 500.
[0018]
The rocker shaft 200 has at least two passages therein. The first passage 210 supplies a lubricant such as a working fluid to the movable member of the valve train. The second passage 220 supplies working fluid to the hydraulic clearance adjusting device 300 disposed on the rocker arm 100.
[0019]
The rocker arm 100 includes a first end 110 and a second end 120. The hydraulic clearance adjustment device 300 is disposed in the cavity 111 of the first end 110 of the rocker arm 100 as shown in FIG. A passage 130 extends from the cavity 111 at the first end 110 of the rocker arm 100 through the interior of the rocker arm 100 and fluidly communicates the hydraulic clearance adjustment device 300 with the second passage 220. The second end 120 of the rocker arm 100 includes a follower assembly 121. The follower assembly 121 follows the shape of the cam projection assembly 600.
[0020]
The hydraulic clearance adjustment device 300 will now be described. The gap adjusting device 300 is mounted in the cavity 111 of the first end 110 of the rocker arm 100 as shown in FIG. The gap adjusting device 300 includes an inner plunger 310 and an outer plunger 320. Outer plunger 320 is received to slide within cavity 111. Inner plunger 310 is received to slide within outer plunger 320.
[0021]
In operation, working fluid flows from passage 130 into cavity 111. The check valve 311 in the inner plunger 310 is pressed downward, allowing fluid flow into the cavity 312 and filling the cavity 312 with fluid. The second check valve 313 located at the lower end of the cavity 312 is pressed downward and into the cavity 330 formed between the lower end of the inner piston (plunger) 310 and the upper end of the outer piston (plunger) 320. Fluid flows. When the cavity 330 is filled with fluid, the outer piston 320 moves down to the extended position and engages the crosshead pin 700. This allows the crosshead pin 700 to actuate at least one valve 710. The downward movement of the outer piston 320 is limited by the engagement of the surface 321 with the surface 112 of the cavity 111.
[0022]
The control assembly 500 controls the operation of the valve 400 to supply a working fluid to the hydraulic clearance adjustment assembly 300. The control assembly 500 can be integrated into the engine control assembly. Alternatively, the control assembly 500 can be a separate control assembly. Valve 400 is preferably a normally open three-way solenoid valve. The control assembly 500 detects engine operating speed, fuel on / off mode, clutch engagement, and various positive power operating conditions to recognize the need to reduce valves.
[0023]
The operation of the rocker arm assembly 10 will be described. During positive power operation, the working fluid flows through the passage 210 of the rocker shaft 200 and provides lubrication including, but not limited to, the rocker arm bushing, the follower assembly 121 and the valve train. The control assembly 500 actuates the valve 400 and supplies the working fluid through the second passage 220 to the passage 130 to actuate the hydraulic clearance adjustment assembly 300. The hydraulic clearance adjustment assembly 300 eliminates any undesirable clearance. This allows the engine to be operated in a valve timing mode that is optimized for a specific engine operating speed.
[0024]
When engine braking is utilized, the control assembly 500 actuates the valve 400 to de-energize the working fluid flow to the hydraulic clearance adjustment assembly 300. The fluid in the cavity 111 and the passage 130 is drained, thereby returning the inner plunger 310 and the outer plunger 320 to the contracted position. As a result, the engine braking rocker arm shown here is operated, and at least one exhaust valve can be operated during engine braking.
[0025]
If the control assembly 500 determines that the valve overlap needs to be changed during positive power operation, the control assembly 500 can actuate the valve 400 of the rocker shaft 200 and cause the hydraulic clearance adjustment device 300 to contract. The valve timing is changed to change the overlap and valve lift as shown in FIG. With the additional valve, the exhaust and intake are operated separately, and only the timing of the exhaust and intake valves can be changed from the set conditions.
[0026]
Although the present invention has been described with respect to specific embodiments thereof, many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention described herein are for purposes of illustration and are not intended to be limiting. Various changes may be made without departing from the spirit and scope of the invention as set forth in the claims.
[Brief description of the drawings]
FIG. 1 is a schematic view of a hydraulic clearance adjustment system according to the present invention.
FIG. 2 is a schematic diagram of a divided hydraulic clearance adjustment system according to the present invention.
FIG. 3 is a graph showing valve timing as modified by the present invention.

Claims (14)

A rocker shaft, an intake rocker arm pivotally attached to the rocker shaft to actuate at least one intake valve of the engine cylinder, and an actuating at least one exhaust valve of the engine cylinder A hydraulic clearance adjustment device comprising an exhaust rocker arm pivotally attached to a rocker shaft and having a compression force releasing brake for operating at least one exhaust valve and at least one intake valve in an engine cylinder Because
Gap adjusting means for adjusting a gap between at least one intake rocker arm and at least one intake valve and between an exhaust rocker arm and at least one exhaust valve, the exhaust rocker arm and the intake rocker The clearance adjustment means comprising an outer plunger slidably received in one cavity of the arm, and an inner plunger slidably received in the outer plunger cavity of the outer plunger;
An apparatus for supplying a working fluid to the gap adjusting means for operating the gap adjusting means, the apparatus including a fluid passage for supplying the working fluid to the gap adjusting means;
Look including a control means for controlling the operation of the device for supplying the working fluid in response to a predetermined engine operating condition,
A hydraulic clearance provided with a compression force release type brake , wherein the control means stops supply of the working fluid to the gap adjustment means of the device for supplying the working fluid during engine braking operation by releasing the compression force Adjustment device . 2. The compression force release according to claim 1, wherein the gap adjusting means is disposed on an intake rocker arm, and the gap adjusting means adjusts a gap between the intake rocker arm and the at least one intake valve. Hydraulic clearance adjustment device with a brake . 2. The compression force release according to claim 1, wherein the gap adjusting means is disposed on an exhaust rocker arm, and the gap adjusting means adjusts a gap between the exhaust rocker arm and the at least one exhaust valve. Hydraulic clearance adjustment device with a brake . 2. The assembly includes a pair of adjusting means for adjusting a clearance between an exhaust rocker arm and at least one exhaust valve and between an intake rocker arm and at least one intake valve. The hydraulic clearance adjustment device provided with the compression force release type brake described in 1. 2. The hydraulic clearance adjusting device with a compressive force releasing brake according to claim 1, wherein the working fluid supplying device is disposed on a rocker shaft. The hydraulic clearance provided with a compression force release type brake according to claim 1, wherein the control means operates a device for supplying the working fluid so as to supply the working fluid to the clearance adjustment means during positive power operation. Adjustment device . 2. The compression force release according to claim 1, wherein after the control unit detects a predetermined engine operating condition, the control unit stops supplying the working fluid to the gap adjusting unit of the device that supplies the working fluid. Hydraulic clearance adjustment device with a brake . 8. The apparatus of claim 7, wherein the control means can operate the apparatus for supplying the working fluid such that the clearance adjustment means improves valve timing of the at least one exhaust valve and the at least one intake valve. Hydraulic clearance adjustment device equipped with a compression release brake . 8. The apparatus of claim 7, wherein the control means can operate a device for supplying the working fluid such that the clearance adjustment means improves a valve lift of at least one of the at least one exhaust valve and the at least one intake valve. In addition, a hydraulic clearance adjustment device equipped with a compression force release type brake . 8. The apparatus of claim 7, wherein the control means can operate the apparatus for supplying the working fluid such that the clearance adjustment means improves an overlap of open times of the at least one exhaust valve and the at least one intake valve. In addition, a hydraulic clearance adjustment device equipped with a compression force release type brake . The clearance adjustment means further comprises an inner plunger cavity formed in the inner plunger, the inner plunger cavity being in selective fluid communication with the outer plunger cavity. A hydraulic clearance adjustment device equipped with a compression force release type brake . 12. The clearance adjustment means further includes a valve assembly disposed within the inner plunger cavity for selective fluid communication between an outer plunger cavity and an inner plunger cavity. A hydraulic clearance adjustment device having a compression force releasing brake as described . 12. The hydraulic clearance adjustment device according to claim 11, wherein the inner plunger includes an opening adapted to allow a working fluid to enter the inner plunger cavity . 14. The hydraulic clearance adjustment device with a brake for releasing a compression force according to claim 13, further comprising a check valve assembly in communication with an opening of the inner plunger .

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