Rocker arm valve mechanism

Abstract

A valve mechanism system in a hydraulic rocker arm for a combustion engine includes a check valve spring, a check valve ball and a control piston. The spring contacting the ball are arranged in a seat in a recess in the arm. The recess has a first opening to a rocker arm channel connected to a hydraulic element and a second opening to a rocker arm oil supply via a second channel. The piston has a first end with a pin axially aligned with the piston arranged in contact with the ball on the opposite side of the ball from the spring. The ball is movable between a first position allowing oil to flow to and from the oil supply and a second position stopping oil from flowing between the two channels. A control piston spring is arranged on a second end of the piston such that it biases the piston towards the ball. The piston in an axial direction is movably arranged in a cylinder shaped cartridge and the cartridge has a first end arranged towards the outside of the arm and a second end in the axial direction opposite inner end. The cartridge is arranged in the recess in the arm.

Claims

1. A valve mechanism system for a hydraulic rocker arm of a combustion engine, the valve mechanism system comprising: recess arranged in the rocker arm, the recess including a first opening fluidly connected to a hydraulic element via a rocker arm channel, and a second opening fluidly connected to a rocker arm oil supply via a second channel; a first seat arranged in the recess; a check valve spring arranged in the first seat; a check valve ball arranged in the first seat so as to be in contact with the check valve spring, the check valve ball configured to be switched between (i) a first position in which a flow of oil between the first and second openings is enabled, and (ii) a second position in which the flow of oil between the first and second openings is prevented; a cylindrical cartridge arranged in the recess, the cartridge including a first p t arranged towards an outside of the rocker arm, and a separately formed second seat part extending towards an inner end of the recess; a control piston slidably arrange d in the first part, the control piston including a first end with an axially extending pin configured to engage the check valve ball at a position opposite to the check valve spring, and a control piston spring pressed between the first part and a second end of the control piston so as to bias the control piston towards the check valve ball, wherein the first part includes outer threads configured to engage in breads of the recess, wherein the second seat part includes at least one radial opening corresponding to the second opening of the recess so as to convey the flow of oil when the check valve ball is in the first position, and wherein the first part is preassembled to the second seat part such that a torque the first part adjusts a sealing function of the second seat part against the recess.

2. The valve mechanism system according to claim 1, wherein the hydraulic element is a piston of the rocker arm.

3. The valve mechanism system according to claim 1, wherein the second seat part further includes an axial opening, and wherein a diameter of axial opening is greater than a diameter of the pin and less than a diameter of the control piston.

4. The valve mechanism system according to claim 1, wherein the second seat part further includes a second seat configured to receive the check valve ball when in the second position.

5. The valve mechanism system according to claim 1, wherein the cartridge further includes an outer circumferential ledge, and wherein the recess further includes a third seat configured to engage the ledge.

6. The valve mechanism system according to claim 1, wherein the second seat part further includes an outer circumferential ledge, and wherein the recess further includes a third seat configured to engage the ledge.

7. The valve mechanism system according to claim 1, wherein the first part further includes a tool engagement structure configured to be engaged by a tool which applies the torque to the first part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of exemplary embodiments of the present invention, wherein:

(2) FIG. 1 is a view of a rocker arm,

(3) FIG. 2 is a cross section along the line A-A of FIG. 1, and

(4) FIG. 3 is cross section along the line C-C of FIG. 1.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

(5) The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness. Like reference character refer to like elements throughout the description.

(6) With reference to FIG. 1 a rocker arm 1 is shown together with cross section lines A-A and C-C.

(7) FIG. 2 relates to the cross section A-A and FIG. 3 to cross section C-C. FIG. 3 shows a valve mechanism system in a hydraulic rocker arm 1 for a combustion engine, comprising a check valve spring 2 and a check valve ball 3. Said spring 2 is arranged in contact with the check valve ball 3 and said spring 2 and ball 3 are arranged in a seat 4 in a recess 5 in the rocker arm 1.

(8) The recess 5 has a first opening 6 to a rocker arm channel 7 connected to a hydraulic element and a second opening 8 to a rocker arm oil supply via a second channel 9. The system further comprises a control piston 10 having a first end with a pin 11 axially aligned with the control piston 10 arranged in contact with said check valve ball 3 on the opposite side of the check valve ball 3 from the check valve spring 2.

(9) The check valve ball 3 is movable between a first position allowing oil to flow to and from the oil supply and a second position stopping oil from flowing between the two channels 7, 9. A control piston spring 12 is further arranged on a second end of the control piston 10 and biases the control piston 10 towards the check valve ball 3.

(10) The control piston 10 is in an axial direction movably arranged in a cylinder shaped cartridge 13 and the cartridge has a first end arranged towards the outside of the rocker arm 1 and a second end in the axial direction opposite inner end. The cartridge is arranged in said recess 5 in the rocker arm 1.

(11) As further can be seen in FIGS. 2 and 3, the second end of the cartridge 13 has an opening 14 that is larger than the diameter of the pin 11 of the control piston 10 and smaller than the control piston diameter. Also, the outside of the second end of the cartridge has a seat 15 for the check valve ball 3.

(12) In the shown embodiment, the cartridge 13 comprises two parts. A first part 16 comprises the first end with an inside cylinder shape to house the control piston 10 and a second seat part 17 that comprises the second end having at least two or more openings 18 for allowing oil to flow to and from a rocker arm oil supply via the second opening 8 in the recess.

(13) Further, the cartridge 13 comprises an outer circumferential ledge 19 with an axially perpendicular plane and a corresponding axially perpendicular plane of a seat 20 in the rocker arm 1. More specifically, in the embodiment shown the second seat part 17 of the cartridge comprises an outer circumferential ledge 19 with an axially perpendicular plane and a corresponding axially perpendicular plane of a seat 20 in the rocker arm 1.

(14) As indicated in FIGS. 2 and 3, the cartridge 13 has outer threads 21 for engaging with inner threads 22 of the recess 5 in the rocker arm 1. More specifically in the embodiment shown, the first part 16 of the cartridge 13 has outer threads 21 for engaging with inner threads 22 of the recess 5 in the rocker arm 1.

(15) In the shown embodiment, the first end of the cartridge 13 has a structure 23 allowing for engagement with a tool, in this case a torx key. Thus, when assembling the valve system, a torx key is used to screw the cartridge 13 into the recess 5. The torque applied should be adapted to the desired sealing function of the circumferential ledge 19 of the second seat part 17 with an axially perpendicular plane of the cartridge against the corresponding axially perpendicular plane of the seat 20 in the rocker arm 1. For making sure the cartridge 13 does not unscrew itself from the recess 5 it could for instance be soldered or welded to the rocker arm 1.

(16) It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims. For example, the structure 23 of the cartridge 13 could be of another type, for instance an outer hexagon shape such that the cartridge 13 is instead screwed into the recess 5 with a wrench.