Patent Publication Number: US-3874225-A

Title: Pressure tester for injector sleeve of diesel engine head

Description:
United States Patent 1191 Fegel 1451 Apr. 1, 1975 1 1 PRESSURE TESTER FOR INJECTOR SLEEVE OF DIESEL ENGINE HEAD [75] Inventor: Albert Fegel, Whittier, Calif.  
 [73] Assignee: Irontite Products Co., Inc., El  
 Monte, Calif.  
 [22] Filed: Oct. 1, 1973 211 Appl. No: 402,463  
 3,029,630 4/1962 Cummins 73/46 Primary Examiner-Charles A. Ruehl Assistant Examiner-John S. Appleman Attorney, Agent, or Firm-Harris, Kern, Wallen &amp; Tinsley 1 1 ABSTRACT A pressure tester for a fuel injector sleeve installed in a diesel engine cylinder head. The pressure tester has at least one seal which isolates the portion of the cavity in the cylinder head in which the injector sleeve is disposed. An air passage admits compressed air through the pressure tester into the interior of the sleeve. A valve in the air pas-sage locks the air under pressure within the sleeve cavity, and a pressure gauge communicating with the air passage inwardly of the valve detects any leakage past the injector sleeve when the valve is closed.  
 13 Claims, 3 Drawing Figures f- AFEHIEQ APR I SHEET 1 BF 2 ATENTEB APR 1 I975 SHEET 2 0F 2 PRESSURE TESTER FOR INJECTOR SLEEVE OF DIESEL ENGINE HEAD BACKGROUND OF INVENTION The present invention relates in general to pressure testers and, more particularly, to a pressure tester for a fuel injector sleeve installed in a diesel engine cylinder head.  
  As background, the cylinder head is provided with a cylindrical cavity extending from the top side of the cylinder head toward the bottom side thereof, the words -top&#34; and bottom being used herein for orientation purposes only. The cylindrical cavity terminates adjacent the bottom side of the cylinder head in a convergent, frusto-conical cavity which, in turn, terminates in a cylindrical opening extending through the bottom side of the cylinder head. The injector sleeve has cylindrical and frusto-conical portions respectively disposed in the cylindrical and frusto-conical cavities in the cylinder head in fluid-tight engagement therewith, theoretically at least.  
  Prior US. patents of some relevance to the present invention which are known to me are:  
 SUMMARY AND OBJECTS OF INVENTION A primary object of the present invention is to provide a very simple and effective pressure tester for a fuel injector sleeve installation of the foregoing nature.  
  One embodiment of the invention may be summarized as including, and an important object is to provide a pressure tester which includes: a tester body having an inner portion insertable into the cylindrical cavity in the cylinder head; a top seal carried by the inner portion of the tester body and engageable with the peripheral wall of the cylindrical cavity in the cylinder head; a member insertable through the cylindrical opening in the cylinder head and threadedly connected to the inner portion of the tester body and having an enlargement externally of the cylinder head and adjacent the bottom side of the cylinder head; a bottom seal on the aforementioned member adjacent the enlargement thereon and engageable with the bottom side of the cylinder head upon tightening of such member; an air passage including a first portion through the tester body and having its inner end in communication with the interior of the sleeve; means for connecting the outer end of the air passage to a source of compressed air; a pressure gauge communicating with the air passage; and a valve outwardly of the pressure gauge and controlliong air flow through the air passage. With this construction, compressed air may be admitted into the interior of the injector sleeve through the air passage described. The valve in the air passage is then closed to trap such compressed air, and any leakage around or past the injector sleeve appears as a decreasing pressure indication by the presssure gauge.  
  The foregoing embodiment of the invention may be further summarized as including, and another object is to provide a pressure tester wherein: the first portion of the air passage is coaxial with the tester body; the aforementioned member is a bolt threaded into the inner end of the first portion of the air passage; the enlargement on the bolt is a bolt head; and the bolt is provided therein with another portion of the air passage, such other air passage portion communicating with the interior of the sleeve. A related object is to provide a construction wherein such other portion of the air passage is an external longitudinal groove in the bolt.  
  Another object is to provide a pressure tester wherein the pressure gauge is carried by the tester body externally of the cylinder head and adjacent the top side thereof.  
  A further object is to provide a pressure tester wherein the top seal is an O-ring and the bottom seal is a washer on the bolt under the bolt head.  
  Yet another object is to provide a pressure tester wherein the tester body has an external annular shoulder thereon which is seatable against the top side of the cylinder head.  
  An important object in connection with another alternative embodiment of the invention is to provide a pressure tester which does not require removal of the cylinder head from the block, and to provide means externally of the cylinder head for clamping the pressure tester thereto, as by bolting.  
  In the foregoing alternative embodiment, the bolt and bottom seal of the first embodiment are omitted as unnecessary.  
  The primary advantage of this alternative form is that the desired leak test of the fuel injector sleeve can be made without disassembling the engine, which is an important feature.  
  The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results which will be evident to those skilled in the injector sleeve pressure testing art in the light of this disclosure, may be achieved with the exemplary embodiment of the invention illustrated in the accompanying drawing and described in detail hereinafter.  
 DESCRIPTION OF DRAWING In the drawing:  
  FIG. 1 is a perspective view of one embodiment of a fuel-injector-sleeve pressure tester of the invention installed in a diesel engine cylinder head, the cylinder head being cut away to show the presssure tester in place;  
  FIG. 2 is a transverse sectional view taken as indicated by the arrowed line 22 of FIG. 1 of the drawing; and  
  FIG. 3 is a view similar to FIG. 1, but showing an alternative embodiment which does not require cylinder head removal.  
 DESCRIPTION OF EXEMPLARY EMBODIMENT OF INVENTION, FIGS. 1 and 2 In the drawing, the numeral 10 designates a fragment of a diessel engine cylinder head having top and bottom sides 12 and 14 and having a cylindrical cavity 16 which extends from the top side of the cylinder head toward the bottom side thereof. This cylindrical cavity terminates adjacent the bottom side of the cylinder head in a convergent, frusto-conical cavity 18 which, in turn, terminates, in a cylindrical opening 20 extending through the bottom side of the cylinder head. Within the cavities 16 and 18 is a fuel injector sleeve 22 having cylindrical and convergent frusto-conical portions 24 and 26 respectively disposed in, and theoretically sealed with respect to, the cylindrical and frustoconical cavities 16 and 18 in the cylinder head 10.  
  The present invention is a pressure tester 30 the function of which is to determine whether the cylindrical and frusto-conical portions 24 and 26 of the sleeve 22 are actually in fluid-tight engagement with the walls of the cylindrical and frusto-conical cavities l6 and 18.  
  The pressure tester 30 includes a tester body 32 having an outer portion 34 and having an external annular shoulder 36 seatable against an internal annular shoulder 37 in the cavity 16. The tester body 32 also has an inner portion 38 insertable into the cylindrical cavity 16 in the cylinder head 10, such inner portion carrying a top seal, preferably an O-ring 40, engageable with the circumferential wall of the cylindrical cavity 16 adjacent the top end of the injector sleeve 22.  
  The pressure tester 30 is provided therethrough with an ir passage 42 which includeds a portion 44 coaxial with and extending through the tester body 32. A bolt or bolt member 46 extends through the cylindrical opening 20 in the bottom side 14 of the cylinder head and into the injector sleeve 22 and is threaded into the inner or bottom end of the passage portion 44. The bolt 46 is provided with an enlargement or head 48 having thereunder an annular bottom seal or washer 50 engageable with the bottom side 14 of the cylinder head upon tightening of the bolt 46.  
  Thus, the O-ring 40 and the washer 50 isolate the portions of the cylindrical and frusto-conical cavities l6 and 18 occupied by the injector sleeve 22 so that any leakage around or past the injector sleeve can be detected by observing whether there is any drop in air pressure within the injector sleeve, as will be described.  
  To admit air from the passage portion 44 into the interior of the injector sleeve 22, the air passage 42 includes another portion 52 communicating with the portion 44 and preferably having the form of an external longitudinal groove 52 in the bolt 46.  
  Carried by the outer portion 34 of the tester body 32 externally of the cylinder head 10 is a pressure gauge 54 which communicates with the portion 44 of the air passage 42 within the tester body 32. In the air passage 42 outwardly of the presssure gauge 54 is a valve 56 which may be opened to admit compressed air into the injector sleeve 22, or which may be closed to lock compressed air therein.  
 Outwardly of the valve 56 is a fitting 58 for connection to a hose, or the like, not shown, leading to a suitable source of compressed air.  
  In operation, the presssure tester 30 is installed in the cylinder head 10 as shown, with the bolt 46 tightened. With the fitting 58 connected to a compressed air source, the valve 56 is opened to admit compressed air into the interior of the injector sleeve 22 and the portions of the cylindrical cavity 16 and the cylindrical opening adjacent the ends of the injector sleeve. Then, the valve 56 is closed to trap such compresssed air, and the operator observes the pressure gauge 54. If the pressure indication on the gauge 54 holds steady, the operator knows there is no leakage past or around the injector sleeve 22. However, if the indication provided by the pressure gauge 54 drops, leakage is indicated, and the injector sleeve 22 must be reinstalled, or  
 a new one installed. Additionally, it may be necessary to resurface the corresponding portions of the cylindrical and frusto-conical cavities 16 and 18.  
  Thus, the present invention provides a very simple and effective pressure tester 30 which can be installed and operated quickly and easily, which are important features.  
 DESCRIPTION OF EXEMPLARY EMBODIMENT OF INVENTION, FIG. 3  
  Shown in FIG. 3 is the same cylinder head fragment 10 as is illustrated in FIG. 1, and identical reference numerals are applied to identical components.  
  Also shown in FIG. 3 is a pressure tester 130 which is similar to the pressure tester 30, and the parts of which are identified by numerals higher by than those used for the corresponding parts of the tester 30. Consequently, such parts need not be described in detail.  
  The tester is used to pressure test the injector sleeve 22 without removal of the cylinder head 10 from the engine block, not shown. Since the head 10 is already sealed relative to the block by the usual head gasket, not shown, the bolt 46 and bottom seal 50 of the tester 30 are not necessary, and are omitted.  
  To secure the tester 130 to the top 12 of the cylinder head 10, a clamping bracket is seated against the cylinder head top and against an external annular shoulder 162 on the tester body 132. The bracket 160 is secured to the cylinder head 10 by screws 164 threaded into the holdes 166 in the head. These holes may be pre-existing, or may be drilled and tapped especially for the purpose.  
  The main advantage of the tester 130 over the tester 30 is, of course, that the cylinder head 10 need not be removed to pressure test the fuel injector sleeve 22. (If the pressure test shows leakage, then, of course, the head 10 must be removed and the sleeve 22 tested with the tester 30 to determine if the sleeve is actually leaking, or if the leak is due to a defective head gasket, or some other factor.)  
  Although exemplary embodiments of the invention have been disclosed for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiments without departing from the invention as herinafter claimed.  
 I claim as my invention:  
  1. A pressure tester for a fuel injector sleeve installed in a diesel engine cylinder head, the cylinder head having a cylindrical cavity extending from the top side of the cylinder head toward the bottom side thereof, the cylindrical cavity terminating adjacent the bottom side of the cylinder head in a convergent, frusto-conical cavity which, in turn, terminates in a cylindrical opening extending through the bottom side of the cylinder head, the injector sleeve having cylindrical and convergent frusto-conical portions respectively disposed in the cylindrical and frusto-conical cavities in the cylinder head, the pressure tester including:  
 a. a tester body having an inner portion insertable into the cylindrical cavity in the cylinder head;  
 b. a top seal carried by said inner portion of said tester body and engageable with the peripheral wall of the cylindrical cavity in the cylinder head;  
 0. a member insertable through the cylindrical opening in the cylinder head and threadedly connected to said inner portion of said tester body and having an enlargement externally of the cylinder head and adjacent the bottom side of the cylinder head;  
 d. a bottom seal on said member adjacent said enlargement and engageable with the bottom side of the cylinder head upon tightening of said member;  
 e. an air passage including a first portion through said tester body and having its inner end in communication with the interior of the sleeve;  
 f. means for connecting the outer end of said air passage to a source of compressed air;  
 g. a pressure gauge communicating with said air passage; and  
 h. a valve outwardly of said presssure gauge and controlling air flow through said air passage.  
 2. A presssure tester as defined in claim 1 wherein:  
 a. said first portion of said air passage is coaxial with said tester body;  
 b. said member is a bolt threaded into the inner end of said first portion of said air passage;  
 0. said enlargement is a head on said bolt; and  
 d. said bolt has another portion of said air passage formed therein, said other portion of said air passage communicating with the interior of the sleeve.  
  3. A pressure tester according to claim 2 wherein said other portion of said air passage is an external longitudinal groove in said bolt.  
  4. A presssure tester as set forth in claim 2 wherein said pressure gauge is carried by said tester body externally of the cylinder head and adjacent the top side thereof.  
  5. A pressure tester according to claim 4 wherein said top seal is an O-ring and said bottom seal is a washer on said bolt under said bolt head.  
  6. A pressure tester as defined in claim 4 wherein said tester body is provided thereon with an external annular shoulder seatable against the cylinder head.  
  7. A pressure tester for a fuel injector sleeve installed in a diesel engine cylinder head, the cylinder head having a generally cylindrical cavity extending from the top side of the cylinder head toward the bottom side thereof, the cylindrical cavity terminating adjacent the bottom side of the cylinder head in a convergent, frusto-conical cavity which, in turn, terminates in a cylindrical opening extending through the bottom side of the cylinder head, the injector sleeve having cylindrical and convergent frusto-conical portions respectively disposed in the cylindrical and frusto-conical cavities in the cylinder head, the cylindrical cavity having an upwardly facing, internal annular shoulder therein above the injector sleeve, the pressure tester including:  
 a. a tester body having an inner portion insertable into the cylindrical cavity in the cylinder head and having an external annular shoulder seatable on said internal annular shoulder to limit insertion of said tester body;  
 b. means for securing said tester body to the cylinder head;  
 c. a top seal carried by said inner portion of said tester body and engageable with the peripheral wall of the cylindrical cavity in the cylinder head above said internal annular shoulder;  
 d. an air passage including a first portion through said tester body and having its inner end in communication with the interior of the sleeve;  
 e. means for connecting the outer end of said air passage to a source of compressed air;  
 f. a pressure gauge communicating with said air passage; and  
 g. a valve outwardly of said pressure gauge and controlling air flow through said air passage.  
  8. A pressure tester as defined in claim 7 wherein said securing means comprises a bolt coaxial with and threaded into said inner portion of said tester body and having a head engageable with the bottom side of the cylinder head.  
  9. A presssure tester as defined in claim 7 wherein said securing means comprises a clamp engaging said tester body and secured to the top side of the cylinder head.  
  10. A pressure tester as set forth in claim 9 wherein said pressure gauge is carried by said tester body externally of the cylinder head and adjacent the top side thereof.  
  11. A pressure tester according to claim 10 wherein said top seal is an O-ring.  
  12. A pressure tester as defined in claim 10 wherein said tester body is provided thereon with an external annular shoulder seatable against the cylinder head.  
  13. A pressure tester for a fuel injector sleeve installed in a diesel engine cylinder head, the cylinder head having a cylindrical cavity extending from the top side of the cylinder head toward the bottom side thereof, the cylindrical cavity terminating adjacent the bottom side of the cylinder head in a convergent, frusto-conical cavity which, in turn, terminates in a cylindrical opening extending through the bottom side of the cylinder head, the injector sleeve having cylindrical and convergent frusto-conical portions respectively disposed in the cylindrical and frusto-conical cavities in the cylinder head, the pressure tester including:  
 a. a tester body having an inner portion insertable into the cylindrical cavity in the cylinder head;  
 b. means for securing said tester body to the cylinder body to the cylinder head, comprising a bolt coaxial with and threaded into said inner portion of said tester body and having a head engageable with the bottom side of the cylinder head;  
 c. a top seal carried by said inner portion of said tester body and engageable with the peripheral wall of the cylindrical cavity in the cylinder head;  
 (1. an air passage including a first portion through said tester body and having its inner end in communication with the interior of the sleeve;  
 e. means for connecting the outer end of said air passage to a source of compressed air;  
 f. a pressure gauge communicating with said air passage; and  
 g. a valve outwardly of said pressure gauge and controlling air flow through said air passage.