GB2490962A

GB2490962A - Workpiece assembly state detection apparatus

Info

Publication number: GB2490962A
Application number: GB201108508A
Authority: GB
Inventors: Stephen Rogers; Luiz E Saoncela; David Tunks
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2011-05-20
Filing date: 2011-05-20
Publication date: 2012-11-21
Anticipated expiration: 2031-05-20
Also published as: GB2490962B; GB201108508D0

Abstract

Workpiece assembly state detection apparatus 10 detects an assembly state of a workpiece 41 to a mechanical apparatus. The workpiece 41 may be an injector assembled to a cylinder head. The assembly state detected is then the number of washers between the injector and the cylinder head. The apparatus is provided with: at least one detection pin 12 disposed so as to be movable when pushed by a workpiece 41; a pair of sensors 13A, 13B disposed at positions different from each other in a movement direction of each detection pin 12 and configured to detect the position of the detection pin 12; and a notification device 14 configured to judge the assembly state of the workpiece 41 based on the detected position of the detection pin 12 and to notify the assembly state. If the injector has been assembled with no washers between the injector and cylinder head the height of the injector is low and the depth the rod 12 extends into the cylinder is such that neither sensor 13a nor 13b is triggered fig. 5A, with one washer one sensor is triggered fig. 5B, with two washers both sensors are triggered fig. 5C.

Description

WORKPIECE ASSEMBLY STATE DETECTION APPARATUS

BACKGROUND OF THE INVENTION

cFIELIJ OF THE INVENTION> £ 110001] The present invention relates to a workpiece assembly state detection apparatus for detecting assembly states of workpieces assembled on a mechanical apparatus.

cRELATED ART> [0002] Inacylinderinjectiontypeengine, injectors for injecting fuel into combustion chambers are mounted on a cylinder head thereof. Each of the injectors is attached to the cylinder headby interposingawasherbetween the injectorandthe cylinder head.

[0003] When the washer is assembled between the cylinder head and the injector, there is a high danger that the regular performance of the engine is not delivered if no washer is mounted or if more than a predetermined number of washers are mounted. Hence, it is necessary to inspect whether an assembly state of the injector is proper. However, in a state that the injector is mounted on the engine, it is impossible to check the washer from outside, and it is very difficult to visually detect an improper mounting of the washer. For this reason, the assembly state of the injector has been checked by inserting a measurement tool into the cylinder head! by making the measutement tool come into contact with an upper face of the injector and by checking a height of the injectbr.

[0004] In addition, as a conventional apparatus for judging the assembly state of the workpiece by detecting its height, a workpiece model detection apparatus is known in which while a conveyor for conveying the workpiece is operated, a detection pin is made pressure contact with a hole in the workpiece or air is discharged from an air nozzle, thereby detecting the model of the workpiece (for example, refer to Patent document 1: JP-A-09-OGllO4) [0005] However, in the conventional method in which the assembly state of the injector is checked using the measurement tool, an operator manuallymakes the measurement tool come into contact with the upper face of the injector and then visually checks the height of the injector. Hence, the checking work is complicated and an accuracy of the checking depends on the skill of the operator.

STJ12RY OF THE INVENTION [0006] One or more embodiments of the invention provide aworkpiece assembly state detection apparatus capable of accurately and easily detecting an assembly state of a workpiece and capable of improving working efficiency using a simple mechanism.

[0007] In accordance with one or more embodiments of the invention, a workpiece assembly state detection apparatus 10 may be configured to detect an assembly state of a workpiece 41 to a mechanical apparatus E. The apparatus 10 may include: a detection pin 12 disposed so as to be movable when pushed by the workpiece 41; apairof sensors 13A, 133 disposed at positions being different from each other in a movement direction of the detection pin 12 and configured to detect a position of the detection pin 12; and a notification device 14 configured to judge the assembly state of the workpiece 41 based on a detection result of the position of the detection pin 12 detected by the pair of sensors 13A, 13B and to notify the assembly state.

[0008] Other aspects and advantages of the invention will be apparent from the following description and the appended claims -

BRIEF DESCRIPTION OF THE DRAWINGS

[000911 FIG. 1 is an external perspective view showing a workpiece assembly state detection apparatus according to an exemplary embodiment1 FIG. 2 is a front view showing an internal structure of the workpiece assembly state detection apparatus shown in FIG. 1; FIG. 3A is a perspective view showing a mounted state of a pair of sensors; S FIG. 3B is a front view of the sensors; FIG. 4 is a perspective view showing the workpiece assembly state detection apparatus for detecting an assembly height of injectors mounted on an engine; and FIGS. BA to BC are front Views showing states in which height differences of the injectors in the assembly states of a washer or washers is detected using the pair of sensors.

DETAILED DESCRIPTtON OF EXEMPLARY EMBODIMENT [0010] A workpiece assembly state detection apparatus according to an exemplary embodiment will be described below referring to accompanying drawings. The workpiece assembly state detection apparatus according to this embodiment is an apparatus for detecting an assembly state of each injector serving as a workpiece that is mounted on a cylinder head of an engine serving as a mechanical apparatus while a washer having a predetermined thickness is held therebetween.

[0011) As shown in FIGS. 1 and 2, a workpiece assembly state detection apparatus 10 according to this embodiment is equipped with a guide bar 11; a plurality of detection pins 12 slidably fitted into this guide bar 11; and apluralityof height detection units 30, each of which has a pair of microswitches l3A and 13B serving as sensors for detecting the position of each detection pin 12 by making contact with the detection pin 12; s and a notification device 14 for judging the assembly state of each of a plurality of injectors 41 on the basis of the detection result of the pair of the microswitches 13A and 13B and for notifying the assembly state. Thepluralityof detection pins 12 (four detection pins in the embodiment shown in FIG. 1) and plural sets (four sets in the embodiment shown in FIG. 1) of the height detection units 30 (30A, 30B, 30C and 30D) corresponding to the number of the detection pins 12 are disposed in parallel at predetermined intervals along the guide bar 11.

[0012] The guide bar 11 has a long guide bar body 15; a rear plate 16 on which the plural sets of the height detection units (30A, 3DB, 30C and 30D) are mounted and which is secured to the rear face side of the guide bar body 15 with screws (not shown); and a front plate 17 secured to the front face side of the guide bar body 15 with screws. In addition, a pair of installation blocks 18 is mounted on the lower face of the guide bar body 15. The height of the installation blocks 18 is set so that when the workpiece assembly state detection apparatus 10 is disposed on an engine E, the detection pin 12 located at its reference position in the case that the assembly -.5-state of the injector 41 is proper pushes the upper face of the injector 41, [0013] As shown in FIG. 2, a plurality (four in the embodiment shown in the figure) of guide holes 19 are provided in the guide bar body 15 at predetermined intervals, for example, at the same intervals L as those of the plurality of injectors 41 (see FIG. 5) mounted on the cylinder head 40 of the engine E. The guide hole 19 is a stepped hole having a large diameter hole 19a provided in the upper portion thereof and a small diameter hole 19b provided in the lower portion thereof.

[0014] The detection pin 12 is a stepped shaft slidably fitted into the guide hole 19 (the large diameter hole l9a and the small diameter hole 19b) and has a large diameter portion 12a formed in the middle in its axial direction, a small diameter lower portion l2b extending downward from the large diameter portion l2a and a small diameter upper portion 12c extending upward from the large diameter portion 12a. In the detection pin 12 fitted into the guide hole 19, the step portion formed between the large diameter portion 12a and the small diameter lower portion 12b makes contact with the step portion formed between the large diameter hole 19a and the small diameter hole 19b of the guide hole 19, whereby the detection pin 12 is restricted to move downward.

As shown in FIGS 5A to SC in detail, a top plate 20 is fixed on the guide bar body 15. At each position of the top plate 20 corresponding to each guide hole 19, a through hole 20a is formed. The small diameter upper portion 12c of the detection pin 12 penetrates through the through hole 20a, and s the top plate 20 supports the detection pin 12.

In the guide hole 19, a spring 25 is disposed. An upper end of the spring is in contact with the top plate 20. A lower end of the spring is in contact with the large diameter portion l2a. The spring 25 urges the detection pin 12 to a lower side, so as to prevent the detection pin 12 from sticking at any of upward positions (e.g. the positions of FIGS SB and Sc to be hereinafter described).

[00151 Also referring to FIG. 3, the height detection unit 30 is equipped with a sensor holder 31 and the pair of microswitches 13A and 13B mounted on this sensor holder 31. The sensor holder 31 has a sensor mounting portion 31a and a guide portion 31b extending sideways from the sensor mounting portion 3la like eaves and is formed into a nearly L shape in cross section.

The sensor mounting portion 31a is provided with a long hole 32 being long in the up-down direction so as to be secured to the rear plate 16 with screws while the height of the height detection unit 30 is adjusted.

[0016] The guide portion 31b is provided with a through hole 34 having an inside diameter being equal to the outside diameter -7-.

of the detection pin 12 and passing through in the up-down direction, and the small diameter upper portion 12c is slidably fitted into the through hole 34. In addition, the upper face of the guide portion 31b is formed into a stepped shape having s left and right faces being different in height while the center axis of the through hole 34 is used as the boundary therebetween.

tO 017] The pair of microswitches 13A and 118 is secured to a side face of the sensor mounting portion 31a with screws 35 at heights being different from each other in the movement direction of the detection pin 12 and corresponding to the difference in height at the step of the guide pOrtion 3lb.

A movable contact piece 33a extending obliquely from downward to upward and a fixed contact 33b which is disposed at an upper position and with which the movable contact piece 33a can make contact are provided on each of the opposed faces of the pair of microswitches 13A and 13B. The movable contact pieces 33a of the microswitches are disposed so that the distance between the base portion sides thereof is larger than the outside diameter of the small diameter portion 12c of the detection pin 12 and so that the distance between the upper ends thereof is smaller than the outside diameter of the small diameter upper portion 12c. Hence, the detection pin 12 rising from downward pushes the movable contactpieces 33a sequentially, wherebyeachmovable contact piece 33a makes contact with the fixed contact 33b corresponding thereto. In other words, the microswitches 13A and 133 operate at positions being different from each other in the movement direction of the detection pin 12.

fools] The pair of microswitches 13A and 133 is connected to the notification device 14 using wires (not shown). Furthermore, in the four sensor holders 31 mounted on the rear plate 16 shown in FIG. 2, the two sensor holders 31 disposed on the right side are left-right symmetric with the two sensor holders 31 disposed on the left side. However, in the case that they are mountable on the rear plate 16, it is not always necessary that they are left-right symmetric as described above.

Moreover, even in the case that the fixed contact 33b is not provided for each of the microswitches I3A and 133, it is possible that the state of the contact with the detection pin 12 is detected using only the movable contact piece 33a.

[0019] The notification device 14 indicates the operation state of the microswitches 13A and 133 of each height detection unit 30. A case 21 incorporating electrical circuit components (not shown) is secured to the upper portion of the rear plate 16 via an L-shaped bracket 22. In the notification device 14, three indication lamps 23 corresponding to each of the height detection units 30 (30A, 303, 30C and 30D) are arranged in four vertical lines.

[0020] More specifically, the indication lamps 23 in line Li correspond to the height detection unit 30A, the indication lamps 23 in line L2 correspond to the height detection unit 303, the indication lamps 23 in line L3 correspond to the height detection unit 300, and the indication lamps 23 in line L4 s correspond to the height detection unit 30D. Since three indication lamps 23 are arranged in each line, totally 12 indication lamps 23 are arranged.

[0021] The three indication lamps 23 (23a, 23b and 23c) arranged in the vertical direction are controlled using an electrical circuit (not shown) so that the lower indication lamp 23a lights when both the microswitches 13A and 133 are inactive, so that the intermediate indication lamp 23b lights when one of the microswitches 13A and 133 is active and the other is inactive, and so that the upper indication lamp 23c lights when both the microswitches l3A and 133 are active. Hence1 the operator can easily check the action state of each microswitch 13 by visually checking the lighting states of the indication lamps 2.3 (23a, 23b and 23c) [00221 Next, the operation of the workpiece assembly state detection apparatus according to this embodiment having the above-mentioned configuration will be described below on the basis of FIGS. 4 and 5. The following descriptions are provided to judge whether the assembly state of the injector 41 is proper, that is, whether the mounted state of the washer 42 mounted -10 -on the injector 41 inside the cylinder head 40 of the engine E is proper.

[0023] First, as shown in FIG. 4, the pair of installation blocks s 18 of the workpiece assembly state detection apparatus 10 is mounted on the cylinder head 40. At that time, in the case of the proper assembly state in which one washer 42 is held between the cylinder head 40 and the injector 41, the detection pin 12 pushes theupper face of the injector4l, andthemicroswitch 13A, serving as one of the pair of microswitches 13A and 13B and located at the lower position, becomes active, and the other microswitch l3B located at the upper position becomes inactive as shown in FIG. EA. As a result, the intermediate indication lamp 23b, among the indication lamps 23 of the notification device 14, lights.

[0024] On the other hand, in the case that two washers 42 are held between the cylinder head 40 and the injector 41 as shown in FIG. SC, the detection pin 12 for pushing the injector 41 is guided into the guide hole 19 and slidably moved upward and pushes the movable contact pieces 33a of both the microswitches 13A and 13B, whereby both the microswitches 13A and 13B become active. As a result, the upper indication lamp 23c, among the indication lamps 23 of the notification device 14, lights.

[0025] -11 -Furthermore, in the case that no washer 42 is held between the cylinder head 40 and the injector 41 as shown in FIG. SA, boththemjcroswjtches l3Aand l3Bbecome inactive. As a result, the lower indication lamp 23a, among the indication lamps 23 S of the notification device 14, lights.

[0026] Consequently, when the detection pin 12 makes contact with both the microswitches 13A and 13B or makes contact with neither of them, in other words, in the case that the height of the injector 41 is too much higher or lower than the regular assembly height thereof, the notification device 14 judges that the assembly state of the injector 41 is improper. When the detection pin 12 makes contact with only the microswitch 13A, in other words, in the case that the height of the injector 41 is equal to the regular assembly height, the notification device 14 judges that the assembly state of the injector 41 is proper.

The color of the intermediate indication lamp 23b for indicating that the assembly state is proper is different from the color of the upper and lower indication lamps 23a and 23c for indicating that the assembly state is improper. For example, in this embodiment, the color of the intermediate indication lamp 23b is green, and the color of the upper and lower indication lamps 23a and 23c is red.

[0027] Hence, in the case that the green indication lamp 23 in each of all the lines Li, L2, 13 and L3 lights, it is possible to check that each injector 41 is in its proper assembly state.

On the other hand, in the case that either one of the red indication lamps in each line lights, it is possible to check that the injector 41 corresponding thereto is in its improper assembly state.

£0028] As described above, the workpiece assembly state detection apparatus 10 according to this embodiment is equipped with *the detection pins 12 being movable when pushed by the injectors 41; the pair of microswitches 13A and 133 disposed at positions being different from each other in the movement direction of each detection pin 12 to detect the position of the detection pin 12 by making contact with the detection pin 12; and the is notification device 14 for judging the assembly state of each injector 41 on the basis of the detection result of the position of the detection pin detected using the pair of microswitches 13A and 133 and for notifying the assembly state, whereby the assembly state of the injector 41 can be detected at three stages using the pair of microswitches l3A and l3B, and the notification device 14 can perform notification according to the assembly state. Hence, it is possible to detect the assembly state of the injector 41 accurately and easily and to improve working efficiency using the simple mechanism described above.

[00291 In addition, the notification device 14 judges that the -13 -assembly state of the injector 41 is improper when the detection pin 12 makes contact with both the microswitches 13A and l3B or makes contact with neither of them, and judges that the assembly state of the injector 41 is proper when the detection pin 12 makes contact with only the microswitch 1324. Hence, the notification device 14 can accurately judge the assembly state of the injector 41.

[00301 Furthermore, when the injector 41 is mounted while the washer or washers 42 having the predetermined thickness are held between the injector 41 and the cylinder head 40, the notification device 14 indicates that the assembly state of the injector 41 is proper or not on the basis of the detection result of the position of the detection pin detected using the pair of microswitches 1324 and 13B. Hence1 the assembly state of the washer or washers 42 mounted on the injector 41 inside the cylinder head 40 can be detected accurately in a short time using the simple mechanism.

[00311 Moreover, since the guide bar 11 in which the plurality of detection pins 12 and the plural sets of the pair of microswitches 1324 and 13B corresponding to the number of the detection pins 12 are arranged in parallel at the predetermined intervals is provided, the assembly states of the plurality of injectors 41 canbe detected simultaneously, and the detection time for detecting the assembly states of the injectors 41 -14 -can be shortened significantly.

[0032] The present invention is not limited to the above mentioned specific exemplary embodiment but can be modified and improved S as necessary.

For example, although it has been described in this embodiment that the notification device notifies the assembly states using the lighting of the indication lamps, the notification device according to the present invention is not limited to use the indication lamps but can use any given device, such as an audio device or a vibratory device, provided that the device acts on the five senses of the human being.

[0033] Still further1 although it has been described that the detection apparatus according to the exemplary embodiment judges whether the assembly state of the washer mounted on the inj ector is proper by detecting the assembly height of the injector mounted on the engine, the present invention is not limited to this embodiment. For example, it is possible to judge whether the assembly state of any given workpiece is proper by detecting the assemblyheight thereof. In particular, since the detection apparatus accordingto thepresent inventiondetects the assembly height of a workpiece using the detection pin, the apparatus is effective for workpieces, the assembly heights of which are difficult to detect visually from outside.

-15 -

[Description of Reference Numerals and Sign]

[0034] workpiece assembly state detection apparatus 11 guide bar 12 detection pin l3A, 13B microswjtches (sensors) 14 notification device cylinder head 41 injector (workpiece) 42 washer E engine (mechanical apparatus) -16 -

Claims

I. A workpiece assembly state detectioft apparatus (10) configured to detect an assembly state of a workpiece (41) to a mechanical apparatus (E), the apparatus comprising: s a detection pin (12) disposed so as to be movable when pushed by the workpiece (41); a pair of sensors (13A, 13B) disposed at positions being different fromeachotherinamovement direction of the detection pin (12) and configured to detect a position of the detection pin (12); and a notification device (14) configured to judge the assembly state of the workpiece (41) based on a detection result of the position of the detection pin (12) detected by the pair of sensors (13A, 13B) and to notify the assembly state.
2. Theapparatusaccordingtoclaimj whereinthenotification device (14) is configured to judge that the assembly state * of the workpiece is improper when the detectionpin (12) contacts with both the sensors (13A, 13B) or contacts with neither of them, and to judge that the assembly tate of thA workpiece is proper when the detection pin (12) contacts with only one * * of the sensors (13A, l3B).
3. The apparatus according to claimlor2, whereintheworkpjece is an injector (41) mounted on a cylinder head (40) while interposing a washer (42) having a predetermined thickness -17 -between the injector (41) and the cylinder head (40), and wherein the notification device (14) indicates whether the assembly state of the injector (41) is proper based on the detection result of the position of the detection pin (12) s by the pair of sensors (13A, 13B).
4 The apparatus according to any one of claims 1 to 3, further comprising: a guide bar (11) on which a plurality of the detection pins (12) and plural sets of the pair of sensors (l3A, l3B) corresponding to the plurality of detection pins (12) are arranged at predetermined intervals.
5. A workpiece assembly state detection apparatus substantially as hereinbefore described with reference to the accompanying drawing. -18-