KR101898576B1

KR101898576B1 - Jig device for preciseness evaluation of shim in Injector and Method of using the same

Info

Publication number: KR101898576B1
Application number: KR1020150045428A
Authority: KR
Inventors: 최진석
Original assignee: 최진석
Priority date: 2015-03-31
Filing date: 2015-03-31
Publication date: 2018-09-17
Also published as: KR20160117819A

Abstract

The present invention relates to a jig device for evaluating in-injector precision. This is for evaluating the precision of seaming inside the injector housing or solenoid body while being in close contact with the injector housing or the solenoid body in a disassembled state during the assembling process of the injector. It takes the form of a cylinder having an internal space, And a male screw part integrally formed on an upper end of the vertical extension part and having a predetermined inner diameter and formed with a male screw thread on an outer circumferential surface thereof and a plurality of slits in a vertical direction; A fixing nut screwed to the male threaded portion of the support body and configured to elastically contract and deform the male threaded portion in the radial direction; And an extension rod disposed in the inner space of the support body and detachably fixed to a spindle of a depth gauge extending downward to the inner space side through the male screw portion.
The jig device for evaluating the in-injector precision of the injector according to the present invention as described above can precisely measure the position and thickness of the seam mounted in the injector when the injector is assembled, thereby improving the assembling precision.

Description

Technical Field [0001] The present invention relates to a jig device for evaluating the accuracy of in-injector shim precision and a method of using the jig device.

The present invention relates to a jig device for evaluating in-injector precision.

Diesel engines have higher vibration and noise than gasoline engines. However, diesel engines have been applied to passenger cars since fuel efficiency is excellent, output torque is high and sound insulation technology is developed.

In such a diesel engine, a direct injection type in which fuel is directly injected into a cylinder is employed in order to inject the atomized fuel in a proper amount in a small amount, and a common rail system is a typical direct injection type.

The injector in the diesel engine to which the common rail is applied has a structure in which a high-pressure fuel is ejected through an ejection hole formed in the nozzle tip by moving the needle valve up and down by using an actuator having a piezo element or a solenoid .

That is, the fuel stored in the fuel tank is supplied to the common rail by using the high-pressure pump, and the fuel filled in the common rail is directly injected into the combustion chamber through the injector provided in each cylinder.

On the other hand, as environmental issues have emerged as important issues, regulations on emission of automobiles have been gradually strengthened. For example, the European Union (EU) regulates the emission of nitrous oxide in diesel vehicles from Euro 6 (Euro 6) in 2013 to less than 0.4 gkWh.

In order to satisfy such regulations and to completely burn the fuel, it is important to inject the correct amount of fuel into the combustion chamber and increase the injection pressure of the fuel to atomize the fuel.

However, if the use time of the engine becomes long and the wear of the parts inside the injector and the adhesion of the impurities become severe, if the impurities are fixed between the valve and the valve seat surface, the fuel may leak or the pressure may leak. This causes a balance of the pressure acting on the piston in the engine, as well as the injection timing and injection pressure of the fuel, which in turn decreases the efficiency of the engine and causes incomplete combustion of the fuel.

For this reason, conventionally, when the engine efficiency is deteriorated or the smoke is severe, a method of replacing the injector which is deemed to have a long period of use or defects has been adopted. This raises the cost of repair and does not allow the recycling opportunity of the injector.

For this reason, Korean Patent No. 10-1329918 discloses a maintenance apparatus for a common rail system injector and a maintenance method thereof. The repairing device is intended to remedy the problem caused by unevenness of the seating surface by reworking the seating surface of the valve body by polishing or the like.

However, these maintenance devices functioned to make the seating surface horizontal or vertical through polishing, but could not hold the seam to the seated surface. In other words, it was enough to make room for a new seam. If the position of the seam is not correct or the thickness of the seam is not correct, the elasticity of the spring may not be applied properly and pressure or fuel may leak.

In addition, even if the position of the newly seated shim is measured by using a dial gauge or the like, there is no dedicated equipment such as a jig or a holder for accurately holding the dial gauge, and accurate measurement is impossible.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a jig device for accurately evaluating the position and thickness of a shim mounted in an injector during assembly of the injector, And the like.

In order to accomplish the above object, the present invention provides a jig for evaluating the in-injector precision of an injector, in which the jig device is mounted on an injector housing or a solenoid body in a disassembled state during assembly of the injector, A jig device for evaluating the accuracy of a shim, comprising: a vertically extending vertical extension having a cylindrical shape with an inner space; and a boss having a predetermined inner diameter integrally formed at an upper end of the vertical extension, A supporting body including a male thread portion formed with a plurality of slits in the vertical direction and formed with male threads; A fixing nut screwed to the male threaded portion of the support body to elastically contract and deform the male threaded portion in the radial direction; And an extension rod disposed in an inner space of the support body and detachably fixed to a spindle of a depth gauge extending downward to the inner space side through the male screw portion; Wherein the support body has a handle portion in the form of a disk and the male screw portion is provided at a central upper portion of the handle portion, and the extension rod is a hollow type in which the inside thereof is hollow, Wherein the spindle coupling portion is formed in a male screw shape and is detachably screwed to a female screw hole provided at a lower end portion of the spindle, And a lower end portion of the armature abuts against a spring support jaw on the upper end of the armature unit of the injector so that a portion of the armature unit can be received in the receiving groove of the extension rod, Wherein an inclined surface portion capable of receiving a force from a fixing nut is formed, Inner circumferential surface, characterized in that the pressure surface is formed and that the number of threads, meshing with the female screw portion, a male screw portion to shrink the pressing parts of the slope.

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The support ring may further include a support ring which surrounds the vertical extension part and is fixed to the inside of the injector housing to maintain a relative position of the support body with respect to the injector housing.

According to an aspect of the present invention, there is provided a method of using a jig device for evaluating an in-injector precision of injector, the method comprising: matching a zero point of the depth gauge with a depth gauge set on the jig device; Inserting the jig device into an engaging portion constituting an upper end portion of the injector housing; Allowing the lower end of the extension rod to first reach the upper surface of the spring support jaw of the armature unit while the support body is seated toward the bottom surface of the engagement portion; The support body is continuously lowered while the extension rod first arrives at the spring support jaw so that the lower end portion of the support body is brought into contact with the bottom surface of the engagement portion so that the distance Y between the upper surface of the spring support jaw and the bottom surface of the engagement portion ); Measuring the height difference (Z) of the upper end of the solenoid body with respect to the upper end of the spring mounted inside the solenoid body by placing the jig device on the solenoid body upside down; And determining a difference value (Y-Z) between the interval (Y) and the height difference (Z) to evaluate the in-injector's in-situ precision.

The jig device for evaluating the in-injector precision of the injector according to the present invention as described above can precisely measure the position and thickness of the seam mounted in the injector when the injector is assembled, thereby improving the assembling precision.

1 is a sectional view showing the internal structure of an injector for a general passenger diesel engine.
2 is a partially cutaway exploded perspective view of a jig device for evaluating the in-injector's shim precision according to the first embodiment of the present invention.
3 and 4A and 4B are views for explaining a method of using the jig device shown in FIG.
FIG. 5 is a schematic view showing the structure of an injector for a general large diesel engine.
FIG. 6 is a partially cutaway perspective view of a jig device for evaluating the in-injector's shim precision according to the second embodiment of the present invention.
Figs. 7A and 7B are views for explaining a method of using the jig device shown in Fig. 6. Fig.

Hereinafter, one embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

Basically, the jig apparatus for evaluating the in-injector precision of the injector according to the present embodiment has a configuration in which, when the injector is reassembled, whether or not the seam to be inserted and inserted into the injector housing is a correct thickness is determined through a measuring mechanism. In particular, it provides a jig with a structure that can be used only for an injector in order to assure the precision of the measuring instrument.

1 is a sectional view showing the internal structure of a common injector 11 for a diesel engine. The reason why the general injector 11 is shown and described is to know in advance the internal configuration of the injector.

As shown in the figure, the injector 11 includes an injector housing 21 in which a fuel flow path is formed, a plunger piston 29 provided so as to be able to move up and down on the center shaft portion of the injector housing 21, A needle 25 disposed at a lower portion of the injector housing 29 and downwardly resiliently supported by a spring and a nozzle 27 located at a lower end of the injector housing 21 and surrounding the needle 25 and having a plurality of injection holes, .

An A valve body 57 is positioned above the plunger piston 29 and an armature unit 54 and a solenoid unit 13 are disposed above the A valve body 57. A spring 15 is mounted on the inner center shaft portion of the solenoid portion 13 and a third seal 17 is disposed on the upper portion of the spring 15.

A first seam 19 is inserted between the armature unit 54 and the A valve body 57 and a second seam 23 is disposed below the armature unit 54.

Reference numeral 21c denotes a valve ball. The valve ball 21c opens and closes the flow passage formed in the A valve body 57 and opens the passage in the A valve body 57 when the armature unit 54 is lifted.

The number, size or installation position of the seams depends on the type of injector.

Basically, the shim is a washer-shaped member having a certain thickness and supports the spring so as to have a constant elastic force, for example, by maintaining the gap between the armature plate 54a and the solenoid 13 precisely, . This seam is almost always replaced in the process of rebuilding the injector as the injector is used for a longer time, and the possibility of wear or adhesion of foreign matter becomes very high.

As mentioned above, a plurality of shims are installed in one injector and serve as respective ones.

The second seam 23 in FIG. 1 is spaced from the A valve body 57 and the armature unit 54 and the first seam 19 is spaced apart from the solenoid 13 .

The third seam 17 also controls the spring force of the spring 15 to control the initial lifting pressure of the armature plate 54a. This modification of the three-seam 17 affects the injection timing of the fuel. That is, if the third seal 17 becomes thinner or becomes partially thickened by the adhesive, the distance between the armature plate 54a and the solenoid 13 changes, which causes the up and down movement time of the armature plate 54a to be inaccurate The injection timing is changed.

If the thickness of the third seam 17 is not correct, the injection timing will vary and the output of the engine will drop significantly. The jig device according to the present embodiment is for evaluating the precision of the third seal 17 in particular, so as to grasp whether the replaced third seal 17 has an accurate thickness, whether it is seated correctly, and the like.

Reference numeral 21d denotes a cylindrical portion constituting the upper end portion of the injector housing 21 and engages with the connecting member 61. [ The connecting member 61 serves to fix the solenoid body 75 to the engaging portion 21d. The solenoid body 75 is a part that houses the solenoid unit 13 and the electrodes and the like and is coupled to the upper end of the injector housing 21 by the connecting member 61. Male threads (21a in Fig. 1) are formed on the outer circumferential surface of the engaging portion 21d.

FIG. 2 is a partially cutaway exploded perspective view of a jig 73 for evaluating the accuracy of the in-injector's shim fastness according to the first embodiment of the present invention. FIGS. 3 and 4A and 4B illustrate how to use the jig 73 Fig.

As shown in the figure, the jig device 73 for evaluating the in-injector's in-situ accuracy according to the first embodiment comprises a jig 47 and an extension rod 49. The extension rod 49 is also used with a depth gauge 43.

4A and 4B, the upper end portion of the injector housing 21 (the upper end in the present description is a portion where the armature unit 53 is located) during the assembling process of the injector A supporting body 45 which is inserted into the engaging portion 21d of the injector housing 21 in a state in which the solenoid body 75 is open and provides a supporting force in contact with the lower end surface of the solenoid body 75, And a fixing nut 37 for tightening the male thread portion 45a of the support body.

The support body 45 includes a handle 45b having a disk shape and having a male screw portion 45a at an upper center thereof and a handle portion 45b located at the center of the bottom of the handle portion 45b, 45d extending in the vertical direction.

Particularly, in the male screw portion 45a, a slit 45k and an inclined surface portion 45e are formed. The slit 45k is a gap extending in the vertical direction and narrows when the fixing nut 37 is applied to the male screw portion 45a. Here, the vertical direction is a direction in which the piston 29 ascends and descends.

The inclined surface portion 45e is a portion pressed against the pressing surface 37a formed on the inner peripheral surface of the fixing nut 37. [ When the fixing nut 37 is engaged with the male screw portion 45a, the fixing nut 37 is lowered and the pressing surface 37a presses the inclined surface portion 45e so that the inner diameter of the supporting surface 45c is small Loses. The support surface 45c is in contact with the stem 43b of the depth gauge 43 to fix the stem 43b.

The fixing nut 37 has a female screw portion 37b and a pressing surface 37a on its inner peripheral surface. The female screw portion 37b is a portion that engages with the male screw portion 45a and the pressing surface 37a serves to move the inclined surface portion 45e inward.

The inner space 45d is a passage through which the extension rod 49 passes. The diameter of the internal space 45d is variable as long as it allows the extension rod 49 to move up and down. Furthermore, it is also possible to guide the lifting movement of the extension rod 49 more positively by manufacturing it with the same inner diameter as the diameter of the extension rod 49.

On the other hand, the extension rod 49 is in the form of a hollow shaft with its inside hollowed out, and its lower end is in contact with the spring support step 54b at the upper end of the armature unit 54. [ The spindle engaging portion 49a is located at the upper end of the extension rod 49. [ The spindle engaging portion 49a is detachably engaged with the female screw hole 43d of the spindle 43c.

In particular, a receiving groove 49b is formed at the center of the extension rod 49. [ The receiving groove 49b has a predetermined inner diameter and is open to the bottom, and accommodates a part of the armature unit 54 therein, as shown in Fig. 4A. Since the receiving groove 49b is provided as described above, the lower end of the extending rod 49 can be brought into close contact with the spring supporting step 54b.

The depth gauge 43 has a substantially disc shape and has a stem 43b and a spindle 43c at a lower portion thereof. The stem 43b guides the longitudinal movement of the spindle 43c.

A female screw hole 43d is formed at the lower end of the spindle 43c. The female screw hole 43d is screwed to the spindle engaging portion 49a as a groove formed with a female screw.

The depth gauge is the same as a general dial gauge and measures the length of the spindle 43c entering the stem 43b. It is preferable to use a digital depth gauge rather than an analog depth gauge. This is because the accuracy of the digital depth gauge is high.

A method of evaluating the precision of the thickness and the mounting position of the third seam 17 using the jig device 73 will be described with reference to FIGS. 3 and 4. FIG.

3, the extension rod 49 coupled with the spindle 43c is inserted into the inner space 45d of the support body 45 while the support body 45 is placed on the base 51 So that the lower end of the extension rod 49 reaches the surface plate 51 at least. Needless to say, the fixing nut 37 must be loosely fitted at this time. As described above, if the lower end of the extension rod 49 touches the surface, the zero point of the depth gauge 43 is adjusted and the fixing nut 37 is tightened to completely fix the depth gauge 43 with respect to the support body 45.

When the depth gauge 43 is set to the support body 45 as described above, the support body 45 and the depth gauge 43 are coupled to each other through the coupling portion 21d . At this time, the first seam is removed.

The lower end of the extension rod 49 first reaches the upper surface of the spring support step 54b of the armature unit 54 while the support body 45 is seated toward the bottom surface of the engagement part 21d.

When the lower end of the supporting body 45 is brought into contact with the bottom surface of the engaging portion while the supporting body 45 is continuously lowered with the extension rod 49 first reaching the spring supporting step 54b, An interval (Y) between the upper surface of the spring supporting step 54b and the bottom surface of the engaging portion 21d is displayed.

The support body 45 and the depth gauge 43 are separated from each other and placed on the solenoid body 75 upside down as shown in FIG. The height difference (Z) of the upper end of the corresponding solenoid body 75 is measured.

In this case, it is needless to say that the third seam 17 is provided under the spring 15.

If the Y value and the Z value are obtained through the above process, the difference between the Y value and the Z value is obtained. The difference value (Y-Z) is defined in the product specification by the injector manufacturer. For example, if the actual measurement result is 0.06 mm and the product specification is 0.05 mm, the third seam 17 is polished to make the thickness 0.01 mm thinner. Commercially available seams are slightly thicker than the reference thickness.

If the actual measurement result value is 0.04 mm, the third seam 17 is separated and discarded and the above process is repeated using another third seam.

As described above, if the thickness of the third seam 10 is thicker or thinner than the predetermined thickness, the armature plate 54a may overcome the force of the spring 15, . In most cases, the injector used for a long time changes the constant of the spring 15.

5 is a schematic view showing the structure of an injector 12 for a general large diesel engine.

Hereinafter, the same reference numerals as those described above denote the same members having the same function, and a description thereof will be omitted.

As shown in Fig. 5, the structure of the injector 12 for a large diesel engine has a structure substantially similar to that of the injector 11 for a passenger diesel engine.

As shown in the figure, an A valve body 57, a ball cap 81, a valve ball 21c, and a support member 85 are provided at an upper center of the injector housing 21. An armature unit (54) and a solenoid unit (13) are located above the ball cap (81).

The solenoid unit 13 operates by electric power transmitted from the outside to move the armature unit 54 up and down and has a spring 33 and a third seam 84 therein. The solenoid portion 13 is fixed to the cap 79 in a state of being fitted in the inner region of the engaging portion 21d.

6 is a partially cutaway perspective view of a jig device 74 for evaluating the in-injector precision of injectors according to the second embodiment of the present invention.

Referring to the drawings, it can be seen that the jig device 74 of the second embodiment is applied with an extension rod 41 in the form of a solid shaft. The extension rod 41 is a round bar having a predetermined length and has a spindle engaging portion 41a at an upper end thereof. The spindle engaging portion 41a is detachably coupled to the female screw hole 43d of the spindle 43c.

In addition, a support ring 46 is provided under the support body 45. The support ring 46 receives a vertical extension 45f therein and surrounds the vertical extension 45f. As shown in FIG. 7, the support ring 46 firmly supports the support body 45 vertically while being in contact with the inner surface of the engagement portion 21d. The support ring 46 is slidable in the longitudinal direction of the vertical extension 45f.

FIGS. 7A and 7B are views for explaining a method of using the jig device 74 shown in FIG.

First, with the depth gauge 43 set on the jig device 74, the zero point of the depth gauge 43 is adjusted in the manner described with reference to Fig.

7A, in the injector housing 21 in which the cap 79, the solenoid unit 13 and the armature unit 54 are removed, the support ring (not shown) 46, and the vertical extension 45f is inserted into the support ring 46.

The lower end of the vertical extension 45f that has passed downward through the support ring 46 abuts the upper surface of the support member 85 and the lower end of the extension rod 41 contacts the ball cap 81. [ The interval T is obtained.

7B, the armature unit 87 is turned upside down while the armature plate 86 and the first shaft 83 are assembled, and the upper surface 83 of the first arm shaft 83 on the armature plate 86 The support body 45, the depth gauge 43, and the extension rod 41 are integrated so that the height difference T2 between the upper surface of the first casing 83 and the central axis end is measured.

The spring 88 and the third seam 84 are provided in the armature unit 87 so as to facilitate the measurement of the armature unit 87. The upper step of the armature plate 86 is provided with a first seal (83) are provided.

If the T1 value and the T2 value are obtained through the above process, the difference between the T1 value and the T2 value can be obtained, and it can be confirmed whether the difference value is 0 to 0.01 mm.

For example, if the actual measured value of T1 is 3.999 mm and the measured value of T2 is 4.004 mm, then 4.004 (T2) - 3.999 (T1) = 0.005 mm. If a value less than 0.005 mm is measured, change the thickness to a thicker value (83), and if the value is greater than 0.005 mm, change the thickness to 83 ° (83). Because the used injector has a very small difference between T1 and T2, prepare a grinding or thick seam to satisfy this gap in the market. If this pore is larger than the reference, a lot of backlash is generated, and if it is too small, the injection amount is decreased.

As described above, the seam 83 is provided under the support member 85. If the thickness of the seam 83 is large, the interval T becomes large. If the thickness is small, the T value will be small.

The thickness of the seam 83 is corrected by comparing the T value obtained through the above process with the value on the product specification, that is, the ideal T value. For example, the ideal T value is 1.031 mm. If the measured value is 1.050, the thickness of the seam 83 is thick. Therefore, the seam 83 is pulled out again and thinly polished or another seam 83 is used. When the measured value is smaller than 1.031 mm, the seam 83 is replaced.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

11, 12: injector 13: solenoid portion 15, 88: spring
17: third seam 19: first seam 21: injector housing
21a: male threads 21c: valve ball 21d: engaging portion
23: second seam 25: needle 27: nozzle
29: plunger piston 37: fixing nut 37a: pressing face
37b: female threaded portion 41: extension rod 41a: spindle coupling portion
43: Depth gauge 43b: Stem 43c: Spindle
43d: Female thread 45: Support body 45a: Male thread
45b: Handle portion 45c: Support surface 45d: Inner space
45e: an inclined surface portion 45f: a vertically extending portion 45k: a slit
46: support ring 47: jig 49:
49a: spindle coupling portion 49b: receiving groove 51:
54: armature unit 54a, 86: armature plate 54b: spring support jaw
57: A valve body 61: connecting member 73, 74: jig device
75: Solenoid body 79: Cap 81: Ball cap
83: Shim 85: Support member

Claims

A jig device for evaluating the precision of a plurality of shims in an injector housing or a solenoid body while being in close contact with a disassembled injector housing or a solenoid body during assembly of the injector,
A plurality of slits formed in a vertical direction and having a predetermined inner diameter and formed on the outer circumferential surface thereof with male threads; A support body including a male thread portion;
A fixing nut screwed to the male threaded portion of the support body to elastically contract and deform the male threaded portion in the radial direction; And
An extension rod disposed in an inner space of the support body and detachably fixed to a spindle of a depth gauge extending downward to the inner space side through the male screw portion;
/ RTI >
Wherein the support body has a knob portion in the form of a disk, the male screw portion is provided at a central upper portion of the knob portion,
Wherein the extension rod has a hollow shape in which an interior thereof is hollow and has a receiving groove opened to the bottom and having a predetermined inner diameter,
Wherein the spindle coupling portion is formed in a male screw shape and is detachably coupled to a female screw hole provided at a lower end portion of the spindle,
A lower end portion of the extension rod is in contact with a spring support jaw on the upper end of the armature unit of the injector and a portion of the armature unit can be received in the receiving groove of the extension rod,
An inclined surface portion capable of receiving a force from the fixing nut when the fixing nut is engaged with the male screw portion is formed on the outer peripheral surface of the upper end of the male screw portion,
Wherein an inner peripheral surface of the fixing nut is provided with a female threaded portion engaging with the male thread and a pressing surface for pressing the inclined surface portion to shrink the male threaded portion.

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The method according to claim 1,
Further comprising a support ring which surrounds the vertical extension and is fixed to the interior of the injector housing to maintain a relative position of the support body with respect to the injector housing.

A method of using a jig device for evaluating in-injector precision of injection according to claim 1,
Adjusting a zero point of the depth gauge in a state where a depth gauge is set in the jig device;
Inserting the jig device into an engaging portion constituting an upper end portion of the injector housing;
Allowing the lower end of the extension rod to first reach the upper surface of the spring support jaw of the armature unit while the support body is seated toward the bottom surface of the engagement portion;
The support body is continuously lowered while the extension rod first arrives at the spring support jaw so that the lower end portion of the support body is brought into contact with the bottom surface of the engagement portion so that the distance Y between the upper surface of the spring support jaw and the bottom surface of the engagement portion );
Measuring the height difference (Z) of the upper end of the solenoid body with respect to the upper end of the spring mounted inside the solenoid body by placing the jig device on the solenoid body upside down; And
Evaluating the injector in-situ precision by obtaining a difference value (YZ) between the interval (Y) and the height difference (Z);
Of the jig device for evaluating the accuracy of in-injector shim precision.