Device for quickly adjusting initial engagement characteristics of a clutch

Abstract

An easily installed and quick reacting in-line clutch engagement control device for hydraulically actuated power transmission friction clutches. The device allows a simple way to quickly and precisely limit a friction clutch's initial torque capacity to an easily adjustable pre-set level.

Claims

1. A device that allows an adjustable partial volume of hydraulic fluid to return un-restricted from a clutch slave cylinder back to the clutch master cylinder during a clutch's engagement cycle, with the precise volume of un-restricted return flow determined by adjusting the stroke distance of a piston acting within a suitable hydraulic cylinder assembly, thus allowing quick partial engagement of the clutch up to the point that the piston reaches the limit of it's travel, which creates a near instant but temporary 1st stage level of reduced torque capacity that effectively reduces the inertia induced torque spike that would normally result from sudden clutch engagement, with the device acting in conjunction with an internal or external valve arrangement that controls fluid movement after the piston reaches the limit of it's travel during the clutch engagement cycle, allowing a secondary controlled flow of fluid returning to the master cylinder that allows the clutch to reach a 2nd stage of full clutch torque capacity while also allowing the fluid flow necessary for the devices' internal piston to return to it's at-rest spring biased position, while an internal or external check valve arrangement allows fluid to flow past the piston without restriction while dis-engaging the clutch.

Description

DESCRIPTION OF DRAWINGS

[0021] FIG. 1A is a cross section view of the invention's internal state when at rest, also the invention's PISTON 10 internal reaction to initial fluid flow into the invention through FLUID PORT 20.

[0022] FIG. 2A is a cross section view showing the invention's internal reaction to return fluid flow entering FLUID PORT 21.

[0023] FIG. 3A has arrows showing how ADJUSTABLE STOP ROD 9 can be threaded in/out of ADJUSTABLE REFERENCE HOUSING 8 to change the effective travel distance of PISTON 10.

[0024] FIG. 3B has arrows showing fluid flow directions when pressure is applied to the system's “master cylinder”.

[0025] FIG. 3C has arrows showing fluid flow direction at the mid-point of PISTON 10 travel.

[0026] FIG. 3D has arrows showing remaining fluid flow thru METERING ORIFICE 23 after PISTON 10 comes contact with HOUSING CAP 7.

DESCRIPTION OF INVENTION

[0027] The preferred embodiment of the invention is a suitable cylinderically shaped outer housing assembly containing a spring biased internal piston/valve assembly with an externally adjustable piston travel limiting stop. Ideally it would be plumbed hydraulically in-line between a power transmission clutch's “master cylinder” and it's “slave cylinder” or “hydraulic throwout bearing”.

[0028] FIG. 1A represents the invention's at rest internal orientation with BIAS SPRING 15 pushing PISTON 10 against ADJUSTABLE STOP ROD 9.

[0029] ADJUSTABLE STOP ROD 9 is threaded into ADJUSTMENT REFERENCE HOUSING 8, allowing for an external adjustment of overall PISTON 10 travel distance within HOUSING BODY 6.

[0030] When fluid flows from the clutch release system's “master cylinder” into the invention through FLUID PORT 20, that fluid cannot move PISTON 10 because BIAS SPRING 15 is already holding PISTON 10 against ADJUSTABLE STOP ROD 9.

[0031] The building pressure of fluid entering FLUID PORT 20 then pushes CHECK VALVE 12 off it's seat, allowing fluid to bypass thru the center of PISTON 10 unrestricted. Fluid then exits the invention through FLUID PORT 21 on it's way to actuate the system's “slave cylinder”.

[0032] As an alternate fluid path, an external valve(s) can be plumbed in parallel to FLUID PORT 20 and FLUID PORT 21 as an effective substitute for the functions of CHECK VALVE 12 and CHECK VALVE SPRING 13.

[0033] When actuating pressure is relieved at the FLUID PORTY 20 “master cylinder” end of the system, fluid flow direction reverses, causing fluid to return into the invention through FLUID PORT 21.

[0034] The resulting pressure difference causes the fluid flow into FLUID PORT 21 to quickly seal CHECK VALVE 12 against it's seat, causing pressure to build which then moves PISTON 10 within HOUSING BODY 6, causing PISTON 10 to in-turn compress BIAS SPRING 15.

[0035] The moving PISTON 10 pushes fluid on it's opposite side to exit the invention through FLUID PORT 20, allowing fluid to return unrestricted on it's path back to the system “master cylinder”.

[0036] When a sufficient volume of has fluid entered FLUID PORT 21 to move PISTON 10 to the point that it contacts HOUSING CAP 7 as illustrated by FIG. 2A.

[0037] After the point where PISTON 10 reaches it's limit of travel distance by contacting HOUSING CAP 7, the balance of “slave cylinder” return fluid volume flowing back into FLUID PORT 21 of the invention then becomes controlled by the flow rate through METERING ORIFICE 23.

[0038] METERING ORIFICE 23 further functions to allow the fluid flow necessary to facilitate BIAS SPRING 15 function of returning PISTON 10 to it's at rest position against ADJUSTABLE STOP ROD 9.

[0039] An alternate to METERING ORIFICE 23 is a solenoid valve hydraulically plumbed parallel to the invention's FLUID PORT 20 and FLUID PORT 21. This alternate return flow arrangement facilitates a very rapid return of PISTON 10 to it's at rest position against ADJUSTABLE STOP ROD 9.