US2915914A - Idle speed control device - Google Patents

Description

.Dec. 8, 1959 J. B. BURNELL ET AL 2,915,914

IDLE SPEED CONTROL DEVICE 2 Sheets-Sheet 1 Filed Feb. 10, 1958 HTTOIPIVEY Dec. 8, 1959 J. B. BURNELL ETAL 2,915,914

IDLE SPEED CONTROL DEVICE 2 Sheets-Sheet 2 Filed Feb. 10, 1958 X; 1% L m; m ma y W 4. 7 Z .v J m 1,

United States Patent IDLE SPEED CONTROL DEVICE Application February 10, 1958, Serial No. 714,282

7 Claims. (Cl. 74-472) The present invention relates to an idle speed control device for use with vehicles having high accessory loads and which loads are intermittently applied to the engine. The subject device may be applied to a vehicle having any type of accessory load which renders it necessary to control the carburetor in such a way as to either maintain a constant engine idling speed whether the load is on or 05 or which accessory load increase may require an increase in engine idling speed depending on certain conditions which will subsequently be discussed.

The present idle speed control device is particularly adapted for use with air conditioned vehicles in which the air conditioning mechanism varies considerably the type of carburetor operation required.

Devices are known which are adapted to vary the engine idling speed in accordance with changes in engine loading brought about by intermittently utilized accessories such as air conditioning. Such devices are shown in Patent Number 2,762,235 Berninger et a1. as well as in copending application Serial No. 436,872 Olson et a1., filed June 15, 1954, now Patent No. 2,822,701. These and similar devices, however, have been found not to be sulficiently versatile to comprehend all'the various accessory load conditions under which the engine might be idling.

In general the prior devices will increase the engine idling speed over its normal value or maintain it: constant if the air conditioning unit is energized with'the engine being returned to its normal idling speed or normal throttle setting when the air conditioning system is shut off. In practice, however, there are found to be actually three distinct idling conditions which must be. accommodated with such a device if it is to function properly. Under the first condition, with the air conditioning unit oif the throttle setting must be such as to accommodate normal engine idling which for illustrative purposes might be 450 r.p.m.

In the case of a' vehicle utilizing an automatictransmission, a second situation obtains when the transmission selector lever is in its drive range and the air conditioning unit on. Under these circumstances it is desirable to maintain the engine idling speed at 450 r.p.m. In this case, it is necessary to provide means for increasing the throttle opening to overcome the increased en-, gine load represented by the frictional resistance or drag in the transmission whereby the engine idling speedwill be maintained constant at the suggested 450 r.p.m. In general the prior art devices are capable of accommodating the first two conditions of operation. However, there is a third condition which has not been achievable, in combination with the other two, by previous devices. 7

This third condition obtains when the transmission selector lever is in the park condition with the air conditioning unit on. Under these conditions, that is, the vehicle idling at the curb, there is a high rate of under the h9od heat rejection. It is imperative that the engine idling speed be increased in order that the air con- 2,915,914 f Patented Dec. 8,1959

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. 2 ditioning mechanism may compensate for the high underhood heat rejection rate. If the prior art devices are adjusted so as to coverthis type of operation it will be apparent that under the second condition of operation, that is with the transmission selector lever in the drive range and the air conditioning unit on, that the engine idling speed will be unnecessarily high increasing the tendency of the vehicle to creep.

It is, therefore, the purpose of the present device to provide an idle speed control device which is capable of three-position operation corresponding to the three conditions of accessory-transmission operation set forth above. The subject device enables the engine idling speed to be more closely tailored to the load conditions to which the engine is subjected and which, therefore, insures engine idling operation which is more compatible with engine load requirements. 1

Other objectsand advantages of the present invention will be apparent from a perusal of the detailed description which. follows.

In the drawings:

1 Figure 1 is a' sectional elevational view of the throttle control mechanism;

Figure 1a is a view' along line 1a-1a of Figure 1;

Figure 2 is'a schematic representation of the electrical control circuit for the throttle control mechanism; and

Figures 3 through 5 represent the various operative positions of the throttle control mechanism.

Referring to the drawings, the idle speed control device is indicated generally at 10. Inasmuch as device 10 may be utilized with any type fuel system, no efi'ort will be made to illustrate the fuel system beyond disclosing a throttle valve 12 rotatably mounted within an induction passage 14. Thus it is apparent that the quantity of combustible mixture supplied to the'engine will be varied by rotating the throttle valve'12 to variably restrict the induction p'assage 14; a v v The throttle valve 12 is suitably fixed to a shaft 16 to which an operating arm 18 is also fixed. Throttle arm 18 terminates in a stop portion or projection 20 which, under conditions to be subsequentlydescribed, is adapted to coact with arr-adjustable stop 'member'22 which forms a part of 'theflidl'e speed control mechanism,

At the outset it should be noted that the idle speedcontrol device;10jisintended only-to control the idle speed and thusthe position of'=throttle 12 under conditions when the airconditionin'g system '13 is operative. Other wise the normal carburetor hotand cold idle stops are p;rovided for controlling the idling position of'thethrottle valve 12. Since the hot and cold idle stop members constitute no part of the present invention they have been eliminated from the drawings only to simplifythe illustration of the present invention. Referring now to control device 10, a bracket '24- is provided to permit the device to be suitably mounted on the engine with which it is to be associated. The adjustable stop member 22 comprises the stud member 26 which is adjustably screwed into a sleeve 28, the other end of which is centrally clamped to a diaphragm member 30. The diaphragm 30 is peripherally clamped between casing members 32 and 34. Thus by rotatably adjusting stud member 26 with relation to sleeve 28 the maximum idle speed of control device 10 may be established.

A sleeve or supporting tube 36 is centrally mounted to casing 32 and is adapted to slidably support the sleeve member 28 therewithin. For reasons which will be apparent subsequently, sleeve 28 is provided with a seal 38 which slidably cooperates with supporting tube 36 to maintain the chamber 40 defined by casing 32 and diaphragm 30 substantially airtight. The supporting tube 36 is fixed to casing 32 by bending or spinning over the r merit 50 abuts while the other end inner ends thereof so as to fixedly mount the tube to the casing. As shown in Figure. 1 the control device supporting bracket 24 is fixed to tube 36 and therethrough supports the remainder of control device 10.

A radial flange ."42-is;f orrn,ed at the other. end of. tube 1 36 and provides an; outer stop: fora dished shapespring insert 54.- "Thus once the. a'xialfpositioncof the-disc 52 is established it will not vary'therefrom unless. anadjust ment is made for reasons which will subsequently be' con sidered. Disc 52 and spring.:seati.44are"so related that upon the axial movement pfislee've 28.10 the right, or idle speed decreasingQdirection, the .disciwill. engage'tlie seat;

Continued rightward movement .of the. sleeve and disc will cause spring 50 to be compressed :untilsuchtim'e. as

the inner end 56 of seat-44 abuts'againstthe spring .seat 46 which ends the movement of adjustablestopi22; I

Reinforcing washers 58-.are provided on either side of position in which"; it abuts tube the diaphragm in order;to protect the diaphragm and 7 also to provide a rigid surface adaptedto 'coact with an annular ridge 60 formedon casing member .34. Ridge 60 provides a stop limiting the leftward or throttle opening position of adjustable stop 22.

The means for controlling the actuationof diaphragm 30 will now hedescribed- The diaphragm supporting casing 34 is elongated, or otherwise formed, to provide a cylindrical portion 62 adapted to house control devices which willsubsequently be described. Casing portion 62 is divideclby a wall section 64 which cooperateswith diaphragm 30 to provideacontrol chamber 66. Wall 64 and the remainder of casing 62 in combination with. a cover p late 68 define an additional chamber70 vented to atmosphere through vent port 7 Casing 62 and moreiparticularly wall 6 4 are formed to provide an .enlarge'dbossiportion 72 which threadably receives. a. pipefifsection 74 adaptedto communicate through a T-plug 76 with a source of vacuum. 'A, passage 78 is drilledthrough wall 64-,and communicates pipe 74 andis closed at its other end by. plug 80*; Passage78 includes a restrictionor orifice 82 therein which reduces the vacuumforce adapted to act on diaphragm 30.

Passage 78; communicates through an opening or passage 84 withdiaphragm chamber 66. p r

Casing wall 64 alsoincludesia transverse passage 86 ntersecting passage 78 andopen at its inner end to communicate with chamber 70. A spindle type valve member 88 is slidably mounted'in transverse. passage 86and includes acyIindrical land portion 90 and a frustro-conical land portion 92. The .frustro-conical land portion 92 is disposedmainly exteriorly of transverse passage 86 and s adapted to control the degree of communication between the transverse passage and chamber 70. Cylindrical land 90, on theother hand, controls the vacuum which may be introduced into chamber 66., r

solenoid 94 is mounted on end plate 68 so as to be disposed within chamber 70 in axial alignment with the sp ndle valve 88. A disc-like armature member 96 is fixedly mounted to the spindle valve 88 proximate the frustro-conical land 92. A spring member 98 is seated w thin the Core of the solenoid 94and-is adaptedto bias armature and the spindle valve 88 to the left when the solenoid isnot energized; In this way; the frustro-conical land 92 will blockthetransverse passage 86 from communic ating with the chamber 70., At the-same time, cy.-. lindricall'and 90 will permit the vacuum. introducedf fqm atone end with the boss 72. and r pipe 74 to communicate with the diaphragm chamber 66. By means to be subsequently discussed, solenoid 94 is adapted to be energized when the vehicle gearshift lever 100 is in its park position.

An additional solenoid device 102 is provided for superimposing a control force on the device 10 which reflects the operative condition of the air conditioning unit. Solenoid device 102 will now be described. The T-plug 76 mounted on pipe 74 provides a boss 104 which threadably supports solenoid casing 106. A solenoid coil is disposed within casing 106 which is enclosed by end plates 108 and 110. End plate 108 includes a passage 112 which communicates through a restricted portion 114 with the T-plug and hence the source of vacuum.

A tube 116 is adapted to seat within an enlarged portion of end plate 108 and is supported at its other end upon a boss 118 extending inwardly from end plate 110. Casing boss 118 includes a longitudinally extending passage 120 therethrough which communicates the interior. of tube 116 with the atmosphere.

An'axially fluted armature-valve member 122 is slidably supported. within tube 116 and includes a tapered end portion.124 adapted to coact with the longitudinally extending boss passage 120 to block the fiow therethrough when solenoid l2l isenergized. However, a spring member 1 26 disposedb'etween boss 118 andthe slidable valve member 122' urges the valve member to the. left which communicates the end casing passage 112' with the atmosphere. r

A conduit 128 communicates with end casing passage 112 and at its other end with an opening 130 in diaphragm casing 32. Thus with the solenoid controlled fluted valve 122 in the position shown in Figure *1 the diaphragm control chamber. 40 is vented to the atmosphere.

The means for controlling the solenoids 94 and 121 is shown schematically inFigure Z andwill now be described. Transmission selector. lever 100 is rotatable about its pivot point132 to the varying positions indicated by the letters P, N, D, Loand R signifying the various operating conditions of the transmission. A transmission selector lever controlled switch is indicated generally at 134 and includes a movable contact member 136 articulated through a lever 138 and a link 140 tothe transmis sion selector lever. The movable contact lever 138 is pivoted at 142 and is connected through a lead 143 with the vehicle battery 1 44. Switch 1134 includes the fixed terminals indicated at N and P which correspond to the transmission selector lever positions represented by neutral and park. The fixed terminals N and-P'connect through a lead v146 with solenoid 94.

A switch 148 controlled by the air conditioning actuat- 7 ing mechanism is interposedinlead143 between the battery 144 and the movable contact136 ofswitch 134. The movable contact .136, througha lead 150, energizes solenoid 121 whenever the air conditioning switch 148- is closed. With theair conditioning switch closed and the transmission selector lever'in either the neutral or park positions, both solenoids 94 and 121 will be'energized.

Referring especially to Figures 3, 4 and 5 in conjunction with Figure 2, the operation 'of the control device 10 is as follows. With the air conditioning switch 148 off or open both solenoids 91 and 121 will be deenergized as shown in Figure 2. Under this condition diaphragm chamber 40 will be vented to the atmosphere through conduits 120, 112 and 128. With the solenoid 121 deenergized, restricted passage 114 will provide a limited atmospheric bleed in vacuum pipe 74. However, the vacuum force in the pipe and hence the remainder of the system is not seriously atfected by such bleed; Further, inasmuch as solenoid 94 is also deenergized, spindle valve land 92 will block the communication of transverse passage 86 with atmospherically vented chamber 70 and at the same time .will permitthe vacuum forcein passage 781.to.be communicated to diaphragm chamber 66-Which will cause the. diaphragmlto. be moved to the right as seen in Figures 1 and 3. Under these conditions sleeve disc 52 will engage flange 48 of spring seat 44 compressing spring 50 and moving the adjustable stop 22 to its rightmost position. As a result, throttle valve 12 is positioned by its normal stop members to provide an appropriate idling speed which for illustrative purposes may be 450 r.p.m.

Next with the air conditioning switch 148 on and the transmission selector lever 100 moved to any ofthe drive positions (D, L0 or R) it will be appreciated that it will be necessary to increase the degree of opening of throttle 12 to maintain a constant, e.g. 450 r.p.m., engine idling speed in view of the air conditioning load now imposed on the engine. Accordingly, the movable contact 136 is out of engagement with the fixed contacts N or P under which condition only the solenoid 121 is energized. Under this condition the solenoid controlled fluted valve 122 blocks the atmospheric bleedpassage 120 which permits manifold vacuum to be communicated through passages 114, 112 and 128 to diaphragm chamber 40. In this way the vacuum forces in chambers 40 and 66 substantially neutralize each other. Spring 50, therefore, will now expand and in so doing move the spring seat 44 and with it disc 52 to the left until flanged end 56 of spring seat 44 engages the annular flange 42* of tube 36 leaving the elements in the position shown in Figure 4. In this position the adjustable stop 22 en-' gages the projection 20 of the throttle arm 18 and opens the throttle sufliciently to maintain the desired engine idling speed, e.g. 450 r.p.m.

In the event the vehicle is now parked at the curb with the engine running and the air conditioning unit on it has been found that the rate of heat rejection under the hood is considerably increased. To provide forproper functioning of'the air conditioning system, it is necessary to increase the engine idling speed by an appreciable amount which again for illustrative purposes may be considered to be as much as to 900 r.p.m. Thus with the transmission selector lever now in either the neutral or park position, solenoid 94 will also be energized. Under this condition, the spindle valve 88 is moved to its rightmost position by the armature disc 96 causing the cylindrical land 90 to block the flow of vacuum to diaphragm chamber 66 and at the same time permitting thefrustroconical land 92 to open said chamber to the atmospherically vented chamber 70. Now manifold vacuum is acting only in diaphragm chamber 40. which causes the diaphragm to be moved still further to the left, as shown in Figure 5, until the left diaphragm reinforcing disc 58 abuts the annular shoulder 152 formed on diaphragm casing member 32. This further leftward movement of the-diaphragm 30 will cause the sleeve 28 and the disc 52 to move relative to the spring seat 44 and to move the throttle valve 12 to a more fully opened position which will cause the engine idling speed to be increased in the amount already suggested.

While the mechanism shown in the drawings is fully operative to provide the three throttle settings, as described, it is apparent that various structural modifications may be made in the subject device within the scope of the invention comprehended by the hereinafter appended claims.

We claim:

1. Apparatus for controlling the idling speed of the engine of an automotive vehicle comprising in combination an induction passage for supplying a combustible mixture to said engine, a throttle valve in said passage for controlling the quantity of flow therethrough, means for applying an accessory load to said engine, a transmission selector lever movable to a plurality of driving and non-driving positions, means for moving the throttle toward open position for increasing the idling speed of the engine, a first device controlled by said accessory load controlling means, a second device controlled by said transmission selector lever, said first and second devices cooperating to maintain the throttle moving means in an inoperative position relative to the throttle valve when the accessory load is not applied and the transmission selector lever is in one of its driving positions whereby the throttle valve is disposed in its normal idle position, saidfirst device being adapted to permit said throttle moving means'to open said throttle valve to a second position when said accessory load is applied, and said second device being adapted to permit said throttle moving means to position said throttle valve in a third position more opcn than the second when said transmission selector lever is placed in one of its non-driving positions with the accessory load applied.

2. Apparatus for controlling the idling speed of the engine of an automotive vehicle'comprising in combination an induction passage. for supplying a combustible mixture to said engine, a. throttle valve in said passage for controlling the quantity of flow therethrough, switch means for applying an accessory load to said engine, a transmission selector lever movable to a plurality of driving and non-driving positions, switch means adapted to be actuated by the selector lever when in a non-driving position, means for moving the throttle toward open position for increasing the idling speed of the engine, a first solenoid device controlled by said accessory switch means, a second solenoid device controlled by said transmission selector lever switch means, circuit means electrically'interconnecting the firstand second solenoid devices and the throttle moving means whereby said devices cooperate when deenergized to maintain the throttle moving means in an inoperative position relative to the throttle valve when the accessory load is not applied and the transmission selector selectorlever is in one of its driving positions whereby the throttle valve is disposed in its normal idle position, said first solenoid device when energized by the accessory switch means being adapted to permit said throttle moving means to open said throttle valve to a second position, and said second solenoid device when energized by the selector lever switch means being-adapted-to permit said throttle moving means to position said throttle valve in a third position more open than the first.

3. An apparatus for controlling the idling speed of the engine of an automotive vehicle comprising in combination an induction passage for admitting a combustible charge to said engine, a throttle valve disposed in said passage for controlling the quantity of flow therethrough, a servo mechanism for moving the throttle toward open position for increasing the idling speed of the engine,

said servo mechanism comprising a casing having a movable member disposed therewithin, said casing and movable' 'member defining a pair of chambers on opposite sides' of said movable member, conduit means adapted to admit a vacuum control force to both of said chambers, a first valve means normally biased to a position venting one of said chambers to atmosphere, a second valve means normally biased to a position admitting said vacuum force to the other of said chambers whereby said servo mechanism is rendered inoperative to position the throttle valve whereby the throttle valve is disposed in its normal idle position, means for shifting said first valve means to a position blocking said atmospheric vent in which condition the vacuum force is admitted to both of said chambers permitting the servo mechanism to move said throttle valve to a second idle position, and means for moving said second valve means to a position in which the associated chamber is vented to atmosphere permitting said servo mechanism to move said throttle valve to a third idle position.

4. An apparatus for controlling the idling speed of the engine of an automotive vehicle comprising in combination an induction passage for admitting a combustible charge to said engine, a throttle valve disposed in said passage for controlling the quantity of flow therethrough, a servo mechanism for moving the throttle toward open position for increasing the idling speed of the engine,

bers, a first valve means normallybiased to a position venting one of said chambers, to atmosphere, asecond valve means normally biased to a position admitting said vacuum-force to the other of said chambers wherebysaid servo mechanism is rendered inoperative to position; the throttle valve whereby the throttle valve is disposed in its normal idle position, a solenoid for shiftingsaid first valve means to a position blocking said atmospheric vent in which condition the vacuum .forceis admitted to both of said chambers permitting the servo mechanism to move said throttle valve to, a second idle position, and a solenoid for moving said second valve means to a position in which the associated member is vented to atmosphere permitting said servo mechanismto move said throttle valve to a third idle position. p 5. An apparatus for controlling the idling speed of an engine as set forth in claim 3 in which said servo mech-' anism includes a control rod fixed to said movable memher and which rod is adapted to actuate said throttle valve, a flange member fixed for movement with said control rod, a sleeve member slidably mounted with respect to said control rod for axial movement relative thereto, spring means biasing said sleeve into engagingposition 'with said flange member to move the control rod in a throttle opening direction, stop means to limit the throttle opening movement of said sleeve, said flange member being adapted to engage said sleeve and compress said spring means when said servo mechanism is in its inoperative position, said spring means being adapted to move said. sleeve, flangemember and said control rod 7 to position the throttle valve in said second idleposition when said vacuum force is admitted to both of said servo chambers, and said flange member and controlrod being moved axially away from said sleeve to position said throttle valve in said third idle position when said vacuum force is admitted to the first vented servo chamber.

6. An apparatus for controlling the idling speed of an engine of an automotive vehicle comprising in combination an induction passage for admitting a combustible charge to said engine, a throttle valve disposed in said passage for controlling the quantity of flow therethrough, a servo mechanism for moving the throttle toward open position for increasing the idling speed of the engine, said servo mechanism comprising a diaphragm having chambers formed on opposite sides thereof in open communication with said diaphragm, first conduit means communicating with one of said chambers, second conduit means communicatingwith the otherrof said chambers, a common source of vacuum communicating with each of said conduit means, first and second valve means respectively disposed insaidufirst and second conduit, means,

each of said valve means being adapted to communicate its associated servo chamber with said vacuum source or with the atmosphere whereby said servo mechanism may move the throttle valve to a plurality of open positions.

engine of an automotive vehicle comprising in combination an induction passage for admitting a combustible charge .to said engine, a throttle valve disposed in said passage for controlling the quantity of'flow therethrough, a servo mechanism for moving the throttle toward open position for increasing the idling speedof the engine, said servo mechanism comprising a. diaphragm having chambers formed on opposite sides thereof inopen communication with said diaphragm, first conduit means communicating with one of said chambers, second conduit means communicating with the other of said chambers, a common source of vacuum communicating with each of said conduit means, first and second valve means respectively disposed in said first and second'conduit means, a spring member normally biasing the first valve means to vent the first conduit means and associated diaphragm chamber to the atmosphere, a spring member ,normally biasing the second valve means to admit vacuum to the second conduit means to shift the diaphragm to a position permitting the throttle valve to assume a first idle position, means shifting the firstvalve to admit vacuumto the second conduit means permitting the throttle valve to assume a second idle position and means for opening the second valve means to atmosphere whereby the diaphragm shifts the throttle valve to a third idle position.

References Cited in the file of this patent UNITED STATES PATENTS 7. An apparatus for controlling the idling speed of an

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