Throttle positioning device

Abstract

A positioning device comprising a solenoid, said solenoid having a plunger slidable upon energization of the solenoid, a solenoid stop associated with said solenoid, a stem operatively connected to said plunger and extending through the movable stop to the exterior, an actuator connected to said solenoid stop and operable to move said stop to selected positions, such that when the solenoid is energized, the plunger is moved to engage the stop and move the stem to a predetermined position, the extent of movement being determined by actuation of the actuator to move the stop in predetermined positions.

Description

This invention relates to throttle positioning devices to control the idle speed of an internal combustion engine.

BACKGROUND AND SUMMARY OF THE INVENTION

In order to control the idle speed of an internal combusion engine, it has been common to utilize various types of devices which function to form a stop for the throttle. Such devices have been commonly known as throttle kickers and are shown, for example, in U.S. Pat. Nos. 3,730,153, 3,760,785 and 4,056,082. The devices have been commonly electrically energized solenoids or vacuum actuated diaphragm devices or combinations of the two. In such devices combining a solenoid and a vacuum actuated device, the devices may not have been capable of an anti-dieseling function because when the solenoid is de-energized, vacuum continues to maintain the stem of the device so that the stem cannot return to its original position unless provision is made for relieving the vacuum quickly.

Another problem of the combined type of throttle positioning device has been that the solenoid must have sufficient force to overcome the hysteresis of the vacuum device and the friction of the seals.

In devices utilizing a magnetic stop for the solenoid plunger it is desirable to be able to vary the portion of the magnetic stop.

In accordance with the invention, the positioning device comprises a solenoid having a plunger slidable upon energization of the solenoid, a solenoid stop associated with the solenoid, a stem operatively connected to said plunger, a motor connected to the solenoid stop and operable to move the stop to selected positions, such that when the solenoid is energized, the plunger is moved to engage the stop and move the stem to a predetermined position, the extent of movement being determined by actuation of the motor to move the stop in predetermined positions.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a part sectional longitudinal view of a throttle positioning device embodying the invention.

FIG. 2 is a longitudinal sectional view of a modified form of throttle positioning device.

FIG. 2A is a plan view of a portion of the device shown in FIG. 1.

FIG. 3 is a fragmentary part sectional view of a modified connection between the parts of the stem of the devices shown in FIGS. 1 and 2.

FIG. 4 is a part sectional side view of the connector shown in FIG. 3.

FIG. 5 is a left end view of the connector shown in FIG. 4.

FIG. 6 is a right end view of the connector shown in FIG. 4.

FIG. 7 is a partly diagrammatic view of a modified form of positioning device.

FIG. 8 is a partly diagrammatic view of a further form of positioning device.

DESCRIPTION

Referring to FIG. 1, the throttle positioning device 10 embodying the invention comprises a housing made of two parts including a first metal member 11, a second plastic member 12, the first member 11 being crimped over a portion of the plastic member 12 to hold a diaphragm 13 in position dividing the housing into a first chamber 14 and a second chamber 15.

The diaphragm 13 is connected at its inner periphery to a magnetic stop member 16 that is movable axially of the housing, one end of the device extending through a hub 17 in member 12 and being sealingly engaged by an O-ring 18 positioned in a groove 19 in the hub 17. More specifically, the inner periphery of diaphragm 13 is clamped between washers 20, 21 that are mounted on member 16, a flange 23 being deformed to hold the washers 21, 22 and diaphragm 13 clamped against a radial wall 24. A spring 25 is interposed between housing member 12 and washer 22 to urge the diaphragm to the left and move wall 24 against a stop 26 defined by a metal spacer 27 clamped between the peripheries of housing member 11 and diaphragm 13. Plate 27 engages a groove 24a in the wall of the magnetic stop 16. To facilitate assembly, plate 27 is formed with a keyhole 27a (FIG. 2A) so that the magnetic stop 16 can be telescoped through the enlarged portion of keyhole 27a and then moved radially to engage the groove 24a. Plate 27 functions to reduce dimensional stack up which affects the travel of the magnetic stop and permits more accurate control of the function.

The throttle positioning device further includes a solenoid 28 including a metal solenoid housing 29 and a plastic or rubber end cap 30 supporting a solenoid winding 31 and a plunger 32 slidingly received within a support member 33 for the winding 31. The magnetic stop member 16 has its other end extending into the solenoid support member to define a stop for the plunger 32. A light spring 34 urges the solenoid plunger 32 against the stop member 16.

A throttle positioning stem 35 is adjustably threaded in the plunger 32 and is herein shown as including a first part 36 threaded in the plunger 31 and an axially movable second part 37 slideably extending through magnetic stop 16, although a single stem can be used.

An integral fitment 38 in housing part 12 forms an opening 39 for connection to a source of vacuum to the first chamber. A throttle element 40 connected to the carburetor linkage is yieldingly urged by spring 41 to oppose movement of the stem 35. Spring 41 overcomes the force of spring 34 to hold the stop member 16 and solenoid plunger 32 in position.

When the solenoid is energized, the stem 35 is moved independently of the diaphragm 13 to a first position. When the solenoid is energized and vacuum is applied to the first chamber 14, the position of the stop member 16 is moved by diaphragm 13 permitting the solenoid to move the plunger 31 further so that the stem 35 is moved to a second position. The stem movement to each of the first and second positions is against spring 41 that urges the throttle element 40, when the throttle is released toward an idle position. When the solenoid is de-energized, the spring 41 acting on the throttle element will return the solenoid to another third position independently of whether or not vacuum is being applied to the first chamber 14 to provide an anti-dieseling function.

The throttle positioning device shown in FIG. 2 provides four positions. The throttle positioning device comprises a housing 50 comprising a metal part 51 having its periphery clamped over a plastic part 52 to hold and clamp together a spacer ring 53 and the periphery of diaphragms 54, 55. Spacer ring 53 has a wall 56 which together with diaphragms 54, 55 divides the housing into a first chamber 57, a second chamber 58, a third chamber 59 and a fourth chamber 60. A fitting 61 in housing part 52 defines an opening 62 for connection to vacuum to the chamber 59 and a fitting 63 in spacer ring 53 defines an opening 64 from the third chamber 59 to a second source of vacuum. Diaphragm 55 is clamped between washers 65, 66, are fixed to magnetic stop member 67. Diaphragm 54 is clamped between washers 68, 69 on a guide member 70 slidable on magnetic stop member 67. The guide member 70 sealingly engages an O-ring 71 in a hub 72 on wall 56 of the spacer ring 53.

The magnetic stop member 67 extends axially in one direction through an intermediate wall 73 of the housing part 51 and in the other direction through a hub 74 in the housing part 52 that supports an O-ring 75 held in position by a staked in washer 76 to define a seal between the hub 74 and the stop 67. A spring 77 is interposed between the diaphragm 55 and the housing part 51 to yieldingly urge the diaphragm 55 and the magnetic stop 67 to the left as viewed in FIG. 2.

The housing further includes a solenoid winding 78 supported by a member 79 and end cap 80 within an extension 81 of the housing. The solenoid includes a plunger 82 slideable within the solenoid member 79 and a stem 83 is threaded into the plunger 82 to adjustably position the stem longitudinally thereof. The stem is formed in two parts, as shown, the first part 84 being threaded through the solenoid 82 and the second part 85 slidingly extending through the magnetic stop 67 to the exterior of the housing at the other end. The free end is adapted to be engaged by a spring 87 and connected to the linkage of the throttle so that the free end defines an adjustable throttle stop when the throttle is released and the spring extends the throttle toward its idle position.

As shown by the diagrammatic positions of FIG. 2, when the solenoid is energized, the stem is held against the end of the movable magnetic stop 67 in a first position independently of the diaphragms 54, 55, the diaphragms remaining in the same position.

When the solenoid is energized and vacuum is applied through opening 64 to the chamber 59, the diaphragm 54 moves the magnetic stop 67 and compresses spring 35 permitting the solenoid to move the stem to a second position. When vacuum is applied to the opening 62, the diaphragm 55 is moved further to the right moving movable magnetic stop 67 further so that the magnetic stop 67 is moved to permit the stem to move to a third position.

When the solenoid is de-energized, the stem can be moved by spring loaded throttle element 86, independently of the magnetic stop to another fourth position independently of whether or not vacuum is applied through the opening 62, 64 to provide an anti-dieseling function.

A control plate like control plate 27 can be added to the form shown in FIG. 2 in the same manner as in the form shown in FIG. 1.

In either of the forms of the invention, the stem 35, 83 can be made in one piece. However, it may be difficult to maintain the concentricity required to prevent binding between the stem, the solenoid plunger and the magnetic stop. The two piece construction allows the parts to align without interference.

In order to prevent noise and possible damage that may occur if the two parts moved relatively back and forth axially, a swivel connector 90 is provided between the parts 36, 38 (or 84, 85) of the stem (FIGS. 3-6). The connector 90 preferably comprises a part which is made of plastic such as nylon which has a central wall 91 and axially oppositely extending sets of fingers 92, 93 with radially inwardly extending tabs 94, 95 that snap into and engage grooves 36a, 37a, respectively. This allows for misalignment between the two parts of the stem but limits the relative axial movement between them.

FIG. 7 shows a positioning device 100 including a solenoid valve 101 that has a plunger 102 which pulls in a stem 103 when actuated, and a movable non-rotatable magnetic stop 104. The position of the magnetic stop 104 is controlled by a second actuator 105. This actuator could be of most any type suitable for the exact application. It may be pneumatic, hydraulic or electrical, or be responsive to temperature or pressure. The actuator will function to position the magnetic stop to two or more fixed positions as it was in the prior forms, or it can modulate through an infinite number of positions within its range of travel. The position of the magnetic stop 102 can be changed either before or after the solenoid is energized, depending on the type of actuator and the control system used in a specific application.

FIG. 8 shows a positioning device 110 which uses a thermostatic bimetal coil 111 to turn a screw 112 which mates with threads in the non-rotatable magnetic stop 113 and thereby controls the position of the stop in response to temperature. The position of the solenoid plunger 114 when actuated is controlled by the temperature of the bimetal coil. The outer end of the bimetal coil is attached to the solenoid housing 115 so that the motion of the bimetal due to changes in temperature results in rotation of the screw 112.

Claims

1. A positioning device comprising

a solenoid,

said solenoid having a plunger slidable upon energization of the solenoid,

a solenoid stop associated with said solenoid,

a stem operatively connected to said plunger,

an actuator connected to said solenoid stop an operable to move said stop to selected positions,

said actuator comprising a bi-metallic coil operable to thread the stem relative to said stop.

such that when the solenoid is energized, the plunger is moved to engage the stop and move the stem to a predetermined position, the extent of movement being determined by actuator of the actuator to move the stop to predetermined positions.