US3430437A - Automotive exhaust emission system - Google Patents

Description

March 4, 1969 C.W.SAUSSEL. ETAL 3,430,437

AUTOMOTIVE EXHAUST EMISSION SYSTEM Filed Oct. 5, 1966 Sheet of 2 C's 4H5: 14/. 54055615 Z 5065M; c. ag g /w March 4, 1969 3,430,437

C. W. SAUSSELE ET AL AUTOMOTIVE EXHAUST EMISSION SYSTEM Sheet 3 Filed Octv 5, 1966 Chi i/P165 M4 SAVSSEL f EUGE'A/E' C. BETTO/V/ INVENTORS ATTORNEY United States Patent F AUTOMOTIVE EXHAUST EMISSION SYSTEM Charles W. Saussele, Southiield, and Eugene C. Bettoni,

Troy, Mich, assignors to Holley Carburetor Company,

Warren, Mich, a corporation of Michigan Filed Oct. 5, 1966, Ser. No. 584,432

US. Cl. 60-30 Int. Cl. F01n 1/14, 3/00; (295d 9/00 Claims ABSTRACT OF THE DISCLOSURE This invention relates to internal combustion engine emission control systems wherein certain objectionable engine exhaust components are treated by air supplied to the engine exhaust manifold by an engine driven pump, and more particularly to such a system wherein a manifold vacuum-actuated valve accomplishes independently the functions of at any time relieving excess pump pressure to atmosphere and of cutting off the supply of air to the exhaust manifold and dumping the same to atmosphere upon deceleration of the engine.

Due to the present state and foreseeable Federal laws relating to control of automotive en ine exhaust emissions, many vehicle engines are now provided with the so-called air injection system wherein an engine driven pump supplies an excess of air to the engine exhaust manifold for the purpose of oxidizing certain exhaust components as they leave the exhaust valves. However, it was found that these engines backfire when air is added to the rich fuelair mixtures supplied by the carburetor during over-run deceleration. To eliminate this objectional backfiring, these air injection systems now include a so-called dump valve responsive to the high intake manifold vacuum on deceleration to momentarily completely cut-off the supply of air to the exhaust manifold and to dump this air to atmosphere through the engine air cleaner. It was also found necessary to provide a pressure relief valve for the air pump to protect the system against excessive pressures due to high engine speeds and exhaust back pressures. The functions of relieving excess pressure and dumping air on deceleration are, of course, not related; that is, relieving excess pressure may be required at high engine speed during acceleration, but dumping is required only on deceleration.

Dumping or relieving excess pressure directly to atmosphere, rather than through the air cleaner, is more convenient, but it results in undesirable noise; dumping and relieving through separate passages increases costs.

This invention contemplates a system, and a particular novel combination valve structure, wherein both dumping of air during deceleration and relieving of excess pressure in the system is accomplished independently, through a single opening other than the aircleaner but having air silencing means that is more convenient and less expensive than dumping through the aircleaner.

Accordingly, an object of the invention is to provide an air injection type emission control system having means for relieving excess pressure and for stopping air flow to the exhaust system and dumping the same to atmosphere during deceleration.

Another object of the invention is to provide such a Patented Mar. 4, 1959 ice system wherein dumping occurs for a short predetermined time at the beginning of the deceleration cycle, when backfiring is likely to occur, and not during the entire deceleration cycle.

Another object of the invention is to provide such a system wherein the dumped air is conveniently silenced by inexpensive means.

Another object of the invention is to provide such a system wherein both dumping and pressure relief to atmosphere occurs through the same opening having means for silencing the air emitted therefrom.

Another object of the invention is to provide a system wherein there is no pressure relief opening in the air pump and wherein a combination pressure-responsive device having one valve for preventing flow of air to the exhaust system and a separate co-operating valve for both dumping air to atmosphere when the first valve is closed and for relieving excess pressure in the system, the latter occurring regardless of whether the first valve is opened or closed.

Another object of the invention is to provide such a system wherein the vacuum responsive valve for blocking flow of air to the exhaust system co-operates with a single dump and pressure relief valve formed in the pump so that dumping occurs through the single pressure relief valve opening in the pump when pump pressure is not required, the pump opening being provided with an inexpensive silencer to eliminate objectionable noise during dumping or the pressure relief functions.

Another object of the invention is to provide a vacuum responsive dump valve assembly having novel means by which it may be easily secured to and removed from the pump housing, thereby facilitating assembly and repair.

These and other objects and advantages of the invention will become more apparent by reference to the following specification and the accompanying drawings wherein:

FIGURE 1 is a schematic illustration, partly in crosssection, of an air injection type emission control system embodying the invention, wherein the air pump has no pressure relief opening, pressure relief being through the intake manifold vacuum responsive dump valve assembly.

FIGURE 2 is a cross-sectional view of a silenced dump valve assembly for use in a system wherein the air pump is provided with a pressure relief valve.

FIGURE 3 is a fragmentary cross-sectional view of a pump and dump valve assembly wherein the dump valve structure has no atmospheric opening but co-operates with the pump relief valve so that both dumping and pressure relief occur independently through a single silenced opening in the pump housing.

FIGURE 4 is an exploded perspective view, with a portion thereof rotated out of axial alignment to better illustrate the structure, of the means employed in FIG- URE 3 for assembling the dump valve structure to the pump.

Referring now to the drawings, FIGURE 1 illustrates an engine 10 having an intake manifold 12, an exhaust manifold 14 and an air manifold 16 with branch conduits 18 leading to the exhaust manifold, usually to the branches 20 of the exhaust manifold just beyond the exhaust valves. The conduit 22 leading to the air manifold may have a check valve 24 to prevent exhaust back pressure from entering the conduit 22 leading to the valve assembly 26.

A suitable air pump 28 is driven from the engine 10 by means such as the belt drive 30, the pump output being connected to the valve assembly 26 through the conduit 32. The purpose of the engine driven pump 28 is, of course, to supply air to the exhaust manifold 14 at all times when the engine 10 is running, except during some portion of the deceleration to prevent backfiring, as explained above.

The valve assembly 26 is responsive to a particular higher intake manifold vacuum occurring on deceleration, and its function is to prevent air from being supplied to the air manifold 16, usually for a predetermined period of time when deceleration first begins.

The valve assembly 26 comprises a cast or otherwise suitably formed body 34 having an air inlet 36, an air outlet 38 and a valve seat 40 being formed between the inlet and the outlet. The body 34 is further formed to provide an annular recess 42 having a flange 44 on which a flexible diaphragm 46 is mounted by any means such as coining the flange 44 over the flange 48 of the cylindrical cover 50. The diaphragm 46 is supported at its central portion by the usual washers 52, and a stem 54, secured in the usual manner to the washers 52, extends slidably through the opening 56 in the annular spring seat 58 fixed to the body 34 and thence axially through the valve seat 40.

The valve assembly 26 thus includes an upper chamber 60, which may be vented to atmosphere, between diaphragm 46 and cover 50 and a lower chamber 62 between the diaphragm and the spring seat 58. A helical spring 64 compressed between the spring seat 58 and the adjacent diaphragm washer 52 normally retains the diaphragm 46 in the position shown in FIGURE 1 so that the valve 66 fixedly secured to the stem is held in the open position away from the valve seat 49 and against the spring seat 58 acting as a stop for the valve. A conduit 68 communicates intake manifold vacuum to the diaphragm chamber 62 so that when deceleration intake manifold vacuum reaches a predetermined value, the force of the vacuum acting on the diaphragm 46 overcomes the force of the spring 64 and closes the valve 66 on its seat 40.

The air inlet 36 is formed with a preferably circular opening 70 communicating with a chamber 72 provided by an integral cylindrical wall portion 74 having an axially aligned larger diameter portion 76 at the free end thereof. A porous, sintered metal or other suitable tubular element 78 having air silencing capability is inserted into the larger diameter portion 76 and a cylindrical, closed-end member 80 is fixedly fitted over the end of the silencing member 78, as by coining the edge 82 thereof over the'annular shoulder formed by the larger diameter portion 76. Slots 81 may be formed in the peripheral surface of the member 80 in forming therefrom tabs engaging the free end of the wall 74, the slots providing openings through which air may escape to atmosphere through the air silencing member 78.

The chamber 72 contains a valve 73 normally urged against the seat 86 by the coil spring 88 compressed between the valve flange 90 and the closed end 92 of the cylindrical member 80. The free end 94 of the stem 54 is received loosely in a cavity 95 formed in the valve 73, and when the diaphragm 46 is in its normal raised position so that valve 66 is open, valve 73 is closed.

Operation In the FIGURE 1 system described, the pump 28 supplies air at all times when the engine is operating, the quantity and pressure of air being proportional to the speed of the engine 10. The conduit 68 is continuously sensing engine intake manifold vacuum, and the weaker diaphragm spring 64 and stronger spring 88 are selected so that their combined forces maintain the valve 66 continuously open and air is continuously supplied to the air manifold 16, except when engine manifold vacuum increases substantially to a predetermined value characteristic of a deceleration cycle. This higher vacuum, acting on the relatively large diaphragm 46 provides a force suflicient to overcome the combined forces of springs 64 and 88 and close the valve 66, thus preventing the pumped air from reaching the exhaust manifold 16. It has been found that, to prevent the undesirable backfiring, closing of valve 66 is required only for some short predetermined period of time at the beginning of the deceleration cycle, the timing being provided by the calibrated opening 96 through the diaphragm 46 and the diaphragm washers 52, which permits air from the chamber 60 to reduce the vacuum in chamber 62 and allow the diaphragm spring 64 to return valve 66 to the open position shown.

Whenever valve 66 is closed by deceleration vacuum, the stem 54 also opens valve 73 against the force of its spring 83, allowing the air supplied by the pump 28 to escape to atmosphere through the silencing cylinder 78 and the openings 81.

The spring 88 is selected so that any time that. pump pressure is excessive, as on a high speed acceleration when valve 66 is closed, the valve 73 will open against the force of the spring 88 to bleed the excess pressure to atmosphere. That is, bleeding of excess pressure occurs at any time, regardless of the position of valve 66.

It is thus apparent that the FIGURE 1 structure provides a combined dump valve and pump relief valve assembly 26 that may be employed with an air injection system in which the pump does not have a relief valve, which enables a less expensive pump structure. Since the valve assembly 26 includes its own silenced atmospheric opening for dumped air, the same silenced opening being employed to relieve pump pressures independently of the dumping function, the aircleaner structure need not be complicated with a dump and pressure relief line, the latter being important as a matter of convenience because the aircleaner should be capable, as it now is, of removal by the operator without tools.

Modifications FIGURE 2 is a crosssectional view of a simplified dump valve assembly 95, similar to that shown in FIG- URE 1 except that it may be employed with a system having a pump 28 with a separate relief valve, if one is necessary, or a relief valve elsewhere in the system.

Like parts of FIGURE 2, although differing in minor details of construction, bear the same reference numerals as they do in FIGURE 1. Actually, the FIGURE 1 and FIGURE 2 structures are almost identical, except that FIGURE 2 has no second spring-loaded relief valve 73 co-operating with the dump valve 66. Air supplied by the pump 28 enters through conduit 32 and flows past the normally open valve 66, which may comprise a rubber or other resilient body engaging a seat 97, and out the conduit 22 to the engine air manifold 16. Whenever intake manifold vacuum sensed through conduit 68 exceeds the predetermined value on deceleration, the vacuum acting on the diaphragm 46 closes the valve on its seat 41 against its spring 64 for a predetermined time controlled by the bleed passage 96 through the diaphragm 46 and the washers 52 to close the valve on its seat. When this occurs, the air supplied by the pump 28 merely flows past the closed valve 66, into the chamber 98 and out the simple cylindrical, closed-end, porous sintered metal or other suitable silencing member 109 inserted into the opening 162 in the body 34. A resilient seal 99, fixed on the stem 54, may be provided to seal vacuum chamber 62 against atmospheric air that may enter through element 100.

FIGURES 3 and 4, wherein like reference numerals identify generally similar parts, illustrate a system, including a dump valve assembly 194, wherein the air pump 28 is provided with a pressure relief valve comprising a suitably formed preferably cylindrical housing 106 retained in an opening 108 formed in the pump housing 110 and having an opening 112 at the inner end thereof controlled by a valve 114 normally urged in the closed direction by a coil spring 116 compressed between the valve 114 and the porous silencing member 118 retained by the inwardly extending flange 120 providing an atmospheric opening 122. The valve 114 is formed with a stem or projection 124 extending through the opening 112 so that when the stem 124 is cocked from its normally axial position air delivered by the pump 28 may escape to atmosphere through the silencing member 118.

The dump valve assembly 104 is generally similar in construction and operation to those shown in FIGURES l and 2. When the valve 66 is normally off its seat 441, as shown in FIGURE 3, air supplied by the pump 28 flows past the valve and to the engine air manifold 16 through the conduit 22. When engine intake manifold vacuum, as sensed by the conduit 68, exceeds a predetermined value on deceleration, vacuum acting on the diaphragm 46 urges the valve 66 closed against the force of its spring 64 for a predetermined period of time, as determined by the bleed opening 96. When this occurs, the stem 54, which is attached to the diaphragm 46 and to which the dump valve 66 is secured, moves to the right in FIGURE 3, and a forked member 126 secured to the free end of the stem 54 and straddling the stem 124 cocks the valve 114 to the open position, allowing air supplied by the pump 28 to be dumped to atmosphere through the silencing member 118. As in FIGURE 1, when the dump valve 66 is open, any excess pump pressure can be independently relieved through the relief valve 114 and the silencing member 118 without effecting the operation of dump valve 66.

FIGURE 4 illustrates the specific novel means of releasably securing the dump valve assembly 104 to the pump housing 110. The pump housing 110 is formed with a hollow cylindrical projection 128 having a cut-away portion 130, and the valve assembly body 34 is formed with a mating hollow cylindrical projection 132 adapted to be received in the projection 128 in a manner so that the external and internal grooves 134 and 136 lie in the same plane adjacent one another.

Before insertion of projection 132, the circular crosssection Wire split ring 138 having substantially radially extending prongs 146 is inserted into the groove 134. The ring 138 is formed with an oval free shape so that the oppositely disposed portion 142 thereof adjacent the prongs 140 are disposed partially outside of the groove 134 when the central portion 144 thereof is in the groove. Thus, upon assembly with the ring 138 and the groove 134, the chamfered inner leading edge 146 of the projection 128 cams the round cross-section ring 138 into the groove 134. When the grooves 134 and 136 are adjacent one another, the ring 138 assumes substantially its free position with the side portions 142 of the ring being positioned in the internal groove 136 and the central portion 144 being positioned in the external groove 134. The valve assembly 104 and the pump housing 110 cannot be disassembled until the prongs 140 are squeezed together so as to position the ring 138 entirely within the groove 134. The function of the cut-away portion 130 is to receive and permit access to the prongs 146, as well as to receive the conduit 133 extending from the body 34, and a gasket or seal 148 may be employed.

It will be apparent that this fastening means is not limited to use in the assembly shown, but provides a quick snap-on attachment and locking means for any two members, it being impossible to disassemble the members axially without first squeezing the ring but possible to freely rotate the members relative to one another. Such a fastening device greatly reduces assembly costs and enables repeated disassembly and reassembly while providing a positive lock.

From the above description, it is apparent that the invention provides a unique combination of a pressure relieved injection emission control system and a dump valve wherein the objectionable noise of air under pressure escaping to the atmosphere is avoided, without complicating the aircleaner installation, as would be the case if air were dumped or relieved through the carburetor aircleaner. Further, the dumped and the relieved air can be discharged to atmosphere through the same silenced passage, either through a silenced pump relief opening, if such an opening is provided, or through a silenced opening to atmosphere provided in the dump valve structure itself. In either case, the relief valve may co-operate with the dump valve in a manner so that dumping and relieving may occur independently.

What we claim as our invention is:

1. The combination of an internal combustion engine having intake and exhaust manifolds, an air pump, means operatively connecting said air pump to said engine in order to drive said pump in relation to engine speed, conduit means for delivering air from said pump to said exhaust manifold, first means responsive to the attainment of a predetermined intake manifold vacuum during engine deceleration for preventing delivery of said air through said conduit means to said exhaust manifold during engine deceleration, and second means including an opening to atmosphere for at times discharging substantially all of said air delivered by said pump during engine deceleration, said second means also being effective to relieve any excess air pressure generated by said pump at any time by venting said excess air pressure to atmosphere through said opening.

2. The combination recited in claim 1, wherein said opening is formed in said pump.

3. The combination recited in claim 1, wherein said opening is provided with means for silencing noise caused by said discharged air.

4. The combination recited in claim 3, wherein said silencing means comprises a porous sintered metal element at said opening.

5. The combination recited in claim 1, wherein said first means comprises a valve seat and a co-operating valve member for said conduit, resilient means urging said valve off said seat, pressure responsive means operatively connected to said valve and effective upon attainment of said predetermined intake manifold vacuum to overcome said resilient means and close said valve on said seat, and means for limiting valve closing to a predetermined time interval less than the duration of Said predetermined vacuum.

6. The combination recited in claim 1, wherein said opening to atmosphere is disposed anywhere from the output side of said pump to said first means and said second means includes additionally a valve urged by resilient means to close said opening and means at said opening for silencing noise caused by said discharged air.

7. The combination recited in claim 1, wherein said first and second means are operatively connected by lost motion means thereby enabling relieving of said excess air pressure through said opening even at such times as when said predetermined intake manifold vacuum has not been attained.

8. A combination recited in claim 1, wherein said first and second means are embodied in a single assembly, said assembly comprising a body formed to provide an air inlet and a first air outlet with a valve seat formed therebetween, said assembly being connected in said conduit with said inlet adjacent said pump and said first outlet adjacent said exhaust manifold, a valve positioned adjacent said seat, a cavity formed on said body, said cavity being divided into first and second chambers by a flexible diaphragm, a stem connected to said diaphragm and to said valve, resilient means in one of said chambers urging said valve away from said seat, a conduit between said intake manifold and one of said chambers for communicating vacuum thereto whereby engine deceleration vacuum acting on said diaphragm may oppose said resilient means and move said valve to engage said seat, said single atmopheric opening being formed in said body on the upstream side of said valve, a spring-loaded valve normally closing said opening and a porous closure means for said opening to silence air discharged therethrough, said stem extending beyond said first mentioned valve and engaging said spring-loaded valve when said first mentioned valve is open so that when deceleration vacuum closes said first mentioned valve said spring-loaded valve will be opened.

9. The combination recited in claim 1, wherein said single atmospheric opening is formed through a wall of said pump at the discharge side thereof and said second means includes additionally a spring-loaded valve normally closing said single atmospheric opening, said valve having a projection thereon extending into said pump, and a porous element for silencing air discharged through said atmospheric opening, and wherein said first means is formed as a separate single assembly connected to a Wall of said pump adjacent said second means and having a passage formed therethrough with a seat formed therein, said assembly comprising a body having an inlet passage communicating with said passage through said pump wall and an outlet passage connected to said conduit, said body having a cavity divided into first and second chambers by a flexible diaphragm, a stern connected to said diaphragm and extending through said passage in said pump wall, a valve member secured to said stem for engaging said seat, resilient means normally urging said valve away from said seat and a conduit between one of said chat bers and said intake manifold.

10. The combination recited in claim 9, wherein the means connecting said assembly to said pump comprises adjacent grooves formed in said assembly and said pump and a split ring having a portion thereof disposed in each groove, said ring having means for compressing the same entirely into one groove to permit repeated attachment and removal of said assembly.

11. A vacuum responsive device, comprising a body formed to provide an inlet communicating with an outlet, a cavity isolated by a Wall from said inlet and said outlet, said cavity being separated into first and second chambers by a flexible diaphragm, a passage leading from said first chamber and adapted to be connected to a source of vacuum, said second chamber being in communication with a source of reference pressure, a stem attached to said diaphragm and extending through said first chamber and said isolating wall and through said inlet beyond said body, a valve member fixedly secured to said stern, resilient means urging said valve member toward said first chamber against a stop, the engagement of said valve member with said stop also providing a seal for said first chamber, a calibrated opening through said diaphragm communicating said first chamber with said second chamher, and means for removably connecting said body to a support.

12. A vacuum responsive device, comprising a body formed to provide an inlet communicating with but otT-set from an outlet, a first valve seat between said inlet and said outlet, a cavity divided into first and second chambers by a flexible diaphragm, a source of reference pressure, one of said chambers being in communication with said source of reference pressure, a passage adapted to connect the other of said chambers with a source of vacuum, a stem secured to said diaphragm and extending axially through said first valve seat, a first valve member on said stem for engaging said first seat, resilient means urging said first valve away from said first seat, an opening in said body on the inlet side of said first valve and substantially aligned therewith, a second seat in said opening, a second spring-loaded valve normally engaging said second seat, a porous element secured at said opening so that fluid passing through said opening must pass through said porous element, said stem engaging said second valve in a manner so that said second valve may open when said first valve is open but'closing of said first valve opens said second valve, and a calibrated restriction through said diaphragm communicating said first chamber with said second chamber.

13. A vacuum responsive two-way fluid valve assembly, comprising an inlet adapted for connection to a source of fluid and communicating through a valve chamber with first and second outlets, said second outlet being adapted for connection to a fluid utilizing device, spaced and axially aligned first and second valve seats for said first and second outlets, a two-way valve positioned between said valve seats and movable therebetween, resilient means urging said valve into engagement with said first valve seat to close said first outlet, vacuum responsive means opposing said resilient means and connected to said valve for moving said valve into engagement with said second valve seat to close said second outlet when subjected to a predetermined vacuum, means for limiting the duration of valve closing by said vacuum responsive means to a predetermined period of time shorter than the duration of said predetermined vacuum, means movable with said two way valve for sealing said vacuum responsive means from said first outlet when said valve is moved to a position whereat it is seated on said first valve seat, and means in said first outlet for silencing the escape of air therethrough.

1 4. The combination of an internal combustion engine having intake and exhaust manifolds, an air supply pump, means operatively connecting said air pump to said engine in order to drive said pump in relation to engine speed, conduit means for delivering air from said pump to said exhaust manifold, first means responsive to the attainment of a predetermined intake manifold vacuum during engine deceleration for preventing delivery of said air through said conduit means to said exhaust manifold during engine deceleration, and second means including a muflled opening to atmosphere for at times discharging substantially all of said air delivered by said pump during engine deceleration.

15. A multi-condition sensing valving assembly; comprising a body; a first inlet in said body adapted for communication with a first source of fluid under variable pressure; pressure responsive means carried by said body and having a second inlet adapted for communication with a second source of fluid under variable pressure; a first outlet adapted for communication with a fluidreceiving chamber; a second outlet in said body adapted for communication with an area under atmospheric pressure; a first valve seat between said first inlet and said first outlet; a first normally open valve member situated in proximity to said first valve seat and adapted to at times be moved by said pressure responsive means into sealing engagement with said first valve seat thereby terminating communication between said first inlet and said first outlet; a second valve seat between said first inlet and said second outlet; a second normally closed valve member seated against said second seat to normally prevent communication between said first inlet and said second outlet; and motion transmitting means operatively connecting said second valve member and said pressure responsive means; said pressure responsive means being effective, Whenever said pressure responsive means senses a first condition indicative of said fluid under variable pressure in said second source attaining a predetermined pressure, to move said first normally open valve member to a closed position against said first valve seat and to move said second normally closed valve member to an open position away from said second valve seat thereby terminating communication between said first inlet and first outlet and establishing communication between said first inlet and said second outlet; said pressure responsive means also being effective, Whenever said pressure responsive means senses a second condition indicative of said fluid under variable pressure in said second source attaining a pressure greater than said predetermined pressure, to move said first valve member to an open position with respect to said first valve seat and permit said second valve member to move to a closed position against said second valve seat thereby establishing communication between said first inlet and said first outlet and terminating communication between said first inlet and said second outlet; and said second valve member being elfective, upon sensing a third condition in- 9 l0 dicative of said fluid under variable pressure in said first 2,620,821 12/1952 Leibing 123-103 X source attaining a pressure greater than a preselected 3,031,235 4/1962 Schwartz 137--625.66 X pressure value, to move away from said cooperating sec- 3,106,820 10/1963 Schatfer 60-30 ond valve seat in order to establish a degree of com- 3,236,452 2/1966 Bordeaux 137--625.27 X munication between said first inlet and said second outlet regardless of the conditions sensed by said pressure re- 5 FOREIGN PATENTS spgnsive means, 26,167 6/1920 Denmark.

References Cited JULIUS 13 WEST, Primary Examiner. UNITED STATES PATENTS 10 DOUGLAS HART, Assistant Examiner. 1,373,599 4/1921 Clark l37-630.22 X

2,430,956 11/1947 Scott 137630.22 x 2,484,622 10/1949 Hartman 137-609 X 137-104, 609, 625.27, 625.66, 630.22

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