JP2012145253A - Glow plug assembly structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glow plug assembly structure that prevents damage to a glow plug and an engine when the glow plug is incorrectly mounted.SOLUTION: This glow plug assembly structure is configured as follows.In multiple kinds of glow plugs, heating elements and the main metal fittings have the same appearance, the heating elements have different performances. The rear end of a connection terminal projecting from the rear end of a main metal fitting toward a rear end side or at least a part of an insulator has different shapes for multiple kinds of glow plugs. A first kind of glow plug connector has a connector terminal or a cap which has a shape to be inserted/removed into/from only the insulator or the rear end of the connection terminal of the first kind of the glow plug in the multiple kinds of glow plugs. The first kind of glow plug connector is assembled to the first kind of glow plug.

Description

  The present invention relates to a glow plug assembly structure.

  Conventionally, glow plugs have been used as starting aids for automobile diesel engines. As such a glow plug, a metal glow plug using a sheathed heater in which, for example, a metal coil heater is housed in a sheath tube as a heating element is known (see, for example, Patent Document 1). A ceramic glow plug using a ceramic heater as a heating element is also known (see, for example, Patent Document 2).

  In recent years, such a glow plug is required to have a rapid temperature rise property that shortens the temperature rise time. For this reason, a glow plug is known in which the electrical resistance value of a heating element, which has conventionally been about 1 to 2Ω, is lowered to, for example, 0.3Ω to improve rapid temperature rise. In the case of a conventional glow plug having a high electrical resistance value, the battery is generally connected to a battery via a relay, and control to turn on / off the current is performed by the relay. On the other hand, in the case of a rapid temperature rise type glow plug, for example, a controller that performs PWM control (pulse width modulation control) or the like is provided, and energization is controlled by this controller.

JP 2006-153306 A JP 2010-181068 A

  As described above, in recent years, a rapid heating type glow plug in which the electric resistance value of the heating element is set low has been used. However, such a rapid temperature increase type glow plug is similar in appearance to a conventional glow plug in which the electrical resistance value of the heating resistor is high. For this reason, there is a possibility that a rapid temperature rising type glow plug may be attached to the engine of an automobile having a conventional electric system by mistake. Thus, if a rapid temperature rise type glow plug is attached to an automobile engine having a conventional electric system, the heating element will be heated above the heat-resistant temperature, melted and damaged, and the engine itself was damaged. There is a possibility.

  The present invention has been made in response to the above-described conventional circumstances. An object of the present invention is to provide a glow plug assembly structure capable of preventing damage to a glow plug and an engine due to erroneous mounting of the glow plug.

  One aspect of the glow plug assembly structure of the present invention is a glow plug extending in the axial direction, which is a rod-shaped heating element, a cylindrical metal shell that surrounds and holds the heating element, and the metal shell A connection terminal inserted into the heating element and connected to the rear end side of the heating element; an insulator disposed between the connection terminal and the metal shell; and electrically insulating the connection terminal and the metal shell; A glow plug connector that is connected to the rear end side of the glow plug and electrically connects the glow plug and an external circuit, and is externally attached to the connection terminal of the glow plug, In the glow plug assembly structure comprising: a glow plug connector having a connector terminal electrically connected to the connection terminal; and a cap portion including the connector terminal; And a plurality of types of glow plugs having the same external shape of the metallic shell and different performance of the heating element, the rear end portion of the connection terminal projecting from the rear end of the metallic shell toward the rear end side or The shape of at least a part of the insulator is made different for each of the plurality of types of glow plugs, and the rear end portion of the connection terminal of the first type of the glow plug among the plurality of types of glow plugs or the insulator. A first type of glow plug connector having the connector terminal or the cap portion having a shape that can be inserted and removed only is prepared, and the first type of glow plug connector is assembled to the first type of glow plug. It is characterized by.

  In the glow plug assembling structure of the present invention, the plurality of types of glow plugs having the same external shape of the heating element and the metal shell and having different performance of the heat generator project from the rear end to the rear end side of the metal shell. The shape of at least a part of the rear end of the connection terminal or the insulator is made different for each of the plurality of types of glow plugs, and the rear end of the connection terminal of the first type of glow plug among the plurality of types of glow plugs or A structure in which a first type glow plug connector having a connector terminal or a cap portion having a shape that can be inserted and removed only from an insulator is prepared, and the first type glow plug connector is assembled to the first type glow plug; It has become. Therefore, for example, the shape of the rear end of the connection terminal in the conventional glow plug and the rapid temperature rise type glow plug, or the shape of the insulator is set to a different shape, and only the rapid temperature rise type glow plug, Alternatively, a connector corresponding only to the conventional glow plug is assembled. Accordingly, it is possible to prevent the glow plug connector that should be attached to the rapid temperature rising type glow plug from being attached to the conventional glow plug. Therefore, even if there are multiple types of glow plugs with the same external shape of the heating element and the metal shell, and the performance of the heating element is different, it is mistakenly applied to the engine of a car having a conventional electrical system. It is possible to prevent erroneous mounting such as attaching a plug, and to prevent damage to the glow plug and the engine due to incorrect mounting of the glow plug.

  The glow plug and glow plug connector can be assembled by combining the rear end of the glow plug connection terminal with the connector terminal of the glow plug connector, the rear end of the glow plug connection terminal and the cap of the glow plug connector. It is possible to cope with this by combining the combination with the part, the combination of the glow plug insulator and the connector terminal of the glow plug connector, and the combination of the glow plug insulator and the glow plug connector cap.

  Further, “the heating element and the metallic shell have the same external shape” means that the heating element and the metallic shell have the same shape, length, thickness and the like. Furthermore, “the performance of the heating element is different” means that the heating rate of the heating element and the resistance value are different. Specifically, for example, in a metal glow plug, the material of the coil provided in the heating element, For ceramic glow plugs having different thicknesses and numbers of windings, ceramic materials having different materials and shapes are used.

  In the glow plug assembly structure of the present invention having the above-described configuration, the plurality of types of glow plugs are viewed from the axial direction of the rear end portion of the connection terminal or the insulator projecting from the rear end of the metal shell toward the rear end side. A connector terminal having a shape that can be inserted / removed only at the rear end portion of the connection terminal of the first type glow plug or the insulator among the plurality of types of glow plugs, the shape being different for each type of glow plug. Alternatively, a first type glow plug connector having a cap portion may be prepared, and the first type glow plug connector may be assembled to the first type glow plug. As a result, only the shape of the rear end portion of the connection terminal, the insulator, the connector terminal, or the cap portion is the same even when the plurality of types of glow plugs have the same external shape of the heating element and the metal shell and the performance of the heating element is different. By changing this, it is possible to prevent erroneous mounting such as attaching a rapid temperature rising type glow plug to an automobile engine having a conventional electric system by mistake. Therefore, it is possible to easily prevent the glow plug and the engine from being damaged due to the erroneous installation of the glow plug.

  Furthermore, it is more preferable that the shape of the insulator or the cap portion viewed from the axial direction is different for each of the plurality of types of glow plugs. Because the above glow plug assembly structure can be more easily realized by processing the shape of the insulator and the cap part, which are resin parts, into predetermined shapes, so that the metal parts of the connection terminals and connector terminals are processed. Compared to the case, the manufacturing process can be simplified.

  Further, in the glow plug assembly structure of the present invention having the above configuration, the shape of the rear end portion of the insulator or the connection terminal protruding from the rear end of the metal shell toward the rear end side, as viewed from the rear end side in the axial direction, It can be line-symmetric with respect to a straight line passing through the axis or point-symmetric with respect to a point passing through the axis. Thereby, it can be made to fit in several rotation direction positions, and can be fitted easily.

  Further, in the glow plug assembly structure of the present invention having the above-described configuration, the shape of the rear end portion of the insulator or connection terminal protruding from the rear end of the metal shell toward the rear end side, as viewed from the rear end side in the axial direction, A shape having a convex portion protruding partly outward, a shape having a concave portion recessed partly inward, a polygonal shape, an elliptical shape, or the like can be used.

  Furthermore, in the glow plug assembling structure of the present invention having the above-described configuration, the diameter of the insulator protruding from the rear end to the rear end side of the metal shell is made different for each of the plurality of types of glow plugs. Among them, a first type glow plug connector having a cap portion having an inner diameter that can be inserted / removed only in the insulator of the first type glow plug is prepared, and the first type glow plug is added to the first type glow plug. The connector can be assembled. As a result, without changing the specifications other than the insulator among the glow plug and the glow plug connector, and further changing the outer diameter of the insulator without changing the shape of the insulator, Even if multiple types of glow plugs with the same external shape of the metal shell and different performance of the heating element are used, a rapid temperature rise type glow plug is mistakenly attached to an automobile engine having a conventional electrical system. Mismounting can be prevented. Therefore, damage to the glow plug and the engine due to erroneous mounting of the glow plug can be prevented.

  Furthermore, in the glow plug assembling structure of the present invention having the above-described structure, the thickness of the insulator protruding from the rear end to the rear end side of the metal shell is made different for each of the plurality of types of glow plugs. The connection terminal and the connector terminal can be electrically connected when the glow plug connector is inserted into the first type glow plug so that the cap part comes into contact with the insulator of the first type glow plug. A first type of glow plug connector having a cap portion to be prepared is prepared, and the first type of glow plug connector is assembled to the first type of glow plug. This makes it possible to change the thickness of the insulator without changing the specifications of the glow plug or glow plug connector other than the insulator, and without changing the shape of the insulator. Even if there are multiple types of glow plugs with the same external shape of the metal fittings and different performance of the heating elements, there is an error such as mistakenly attaching a rapid temperature rise type glow plug to an automobile engine having a conventional electrical system. Wearing can be prevented. Therefore, damage to the glow plug and the engine due to erroneous mounting of the glow plug can be prevented.

  According to the present invention, it is possible to provide a glow plug assembly structure capable of preventing damage to the glow plug and the engine due to erroneous mounting of the glow plug.

The figure which shows schematic structure of the glow plug which concerns on one Embodiment of this invention. The figure which shows the cross-sectional schematic structure of the glow plug of FIG. The figure which shows schematic structure of the glow plug connector which concerns on one Embodiment of this invention. The figure which shows the structure of the glow plug which concerns on 1st Embodiment, and a glow plug connector. The figure which shows the structure of the glow plug which concerns on 1st Embodiment, and a glow plug connector. The figure which shows the structure of the glow plug which concerns on 1st Embodiment, and a glow plug connector. The figure which shows the structure of the glow plug which concerns on 1st Embodiment, and a glow plug connector. The figure which shows the structure of the glow plug which concerns on 1st Embodiment, and a glow plug connector. The figure which shows the structure of the glow plug which concerns on 1st Embodiment, and a glow plug connector. The figure which shows the structure of the glow plug and glow plug connector which concern on 3rd Embodiment. The figure which shows the structure of the glow plug which concerns on 4th Embodiment, and a glow plug connector. The figure which shows the structure of the glow plug which concerns on 5th Embodiment, and a glow plug connector. The figure which shows the structure of the glow plug which concerns on 5th Embodiment, and a glow plug connector. The figure which shows the structure of the glow plug which concerns on 6th Embodiment, and a glow plug connector. The figure which shows the structure of the glow plug which concerns on 6th Embodiment, and a glow plug connector.

  Hereinafter, details of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing an overall schematic configuration of the glow plug 1 according to the first embodiment of the present invention, and FIG. 2 is a diagram showing a schematic vertical sectional configuration of the glow plug 1.

  As shown in FIGS. 1 and 2, the glow plug 1 includes a cylindrical metal shell 2 and a sheathed heater 3 (corresponding to a heating element in claims) attached to the metal shell 2.

The metal shell 2, the axial hole 4 penetrating in the axial C ₁ direction is formed. Further, on the outer peripheral surface of the metal shell 2, there are formed a screw portion 5 for attachment to a diesel engine and a tool engaging portion 6 having a hexagonal cross section for engaging a tool such as a torque wrench.

The sheathed heater 3 includes a sheathed tube 7 that houses a heating coil and the like. On the rear end side of the sheath tube 7, an intermediate shaft 8 as a lead member is integrated and fixed in the direction of the axis C ₁ .

  The seed tube 7 is formed of a cylindrical tube made of a metal having a closed end, such as stainless steel or a nickel-based alloy (for example, Inconel (trade name)). In the sheath tube 7, a heating coil (not shown) joined to the tip of the sheath tube 7 and a control coil (not shown) connected in series to the rear end of the heating coil are sealed together with an insulating powder such as magnesium oxide powder. Yes. The middle shaft 8 is joined to the rear end side of the control coil, and the rear end of the sheath tube 7 and the middle shaft 8 are sealed with an annular rubber (not shown).

  The sheath tube 7 is formed with a small-diameter portion 7a that accommodates a heating coil or the like at its tip by swaging or the like, and a large-diameter portion 7b that is larger in diameter than the small-diameter portion 7a at the rear end. ing. As shown in FIG. 2, the large-diameter portion 7 b is press-fitted and joined to the small-diameter portion 4 a formed in the shaft hole 4 of the metal shell 2, so that the sheath tube 7 protrudes from the tip of the metal shell 2. It is held in the state.

  The middle shaft 8 is a metal rod made of carbon steel (for example, SCM435). The front end of the middle shaft 8 is inserted into the sheath tube 7 and is electrically connected to the rear end of the control coil. Is inserted. The rear end of the middle shaft 8 protrudes from the rear end of the metal shell 2, and the rear end side of the middle shaft 8 has an insulating ring 13 made of an annular O-ring 12 and a resin (corresponding to the insulator in the claims). Is fitted. The insulating ring 13 has an enlarged diameter portion on the rear end side, and is engaged with the rear end of the metal shell 2 at the enlarged diameter portion.

  The O-ring 12 is brought into contact with the inner peripheral surface of the shaft hole 4 of the metal shell 2, the outer peripheral surface of the middle shaft 8, and the tip side surface of the insulating ring 13, so that the airtightness in the shaft hole 4 is maintained. ing. The insulating ring 13 positions the middle shaft 8 and the shaft hole 4 of the metal shell 2 in a non-contact state, and the two are electrically insulated.

  A cap-shaped pin terminal 14 is fitted to the rear end portion of the middle shaft 8 protruding from the rear end of the insulating ring 13. The center shaft 8 and the pin terminal 14 constitute a connection terminal connected to the rear end side of the sheathed heater 3 (heating element).

  In the glow plug 1 configured as described above, the sheathed heater 3 is press-fitted and fixed in the shaft hole 4 of the metal shell 2, and the O-ring 12, the insulating ring 13, and the like are fitted into the middle shaft 8 at the rear end portion of the metal shell 2, This is completed by caulking the outer periphery of the pin terminal 14 with the insulating ring 13 pressed against the metal shell 2.

  Next, the glow plug connector 30 connected to the glow plug will be described. FIG. 3 is a diagram showing an overall schematic configuration of the glow plug connector 30 according to the first embodiment of the present invention.

  As shown in FIG. 3, the glow plug connector 30 includes a connector terminal 31 for establishing electrical continuity with the pin terminal 14 and an insulating cap portion 32 that encloses the connector terminal 31. ing. The cap portion 32 is made of an insulating resin or the like. Furthermore, the connector terminal 31 is connected to a lead wire 34 for connection to an external circuit.

  The connector terminal 31 has a shape that can be fitted to the pin terminal 14 and is fitted from the rear end side of the pin terminal 14. On the other hand, the cap portion 32 covers the outside of the rear end portion of the pin terminal 14 when the connector terminal 31 and the pin terminal 14 are fitted (see FIG. 4).

  Here, the pin terminal 14 of the glow plug 1 of the first embodiment has a shape when viewed from the rear end side, which is not simply a circular shape, for example, as shown in FIGS. 5 (a) to 9 (a). It has a shape like this. That is, for example, as shown in FIG. 5A, a rectangular convex portion 40 protruding toward the outer peripheral side is formed on a part of the outer periphery of the pin terminal 14. Therefore, a cap having a circular shape on the tip side of the cap portion, such as a normal glow plug connector, cannot be properly fitted to the glow plug 1. In addition, the position where the shape of the pin terminal 14 is different may be either the rod-shaped portion 91 on the rear end side or the large-diameter portion 92 provided on the distal end side of the rod-shaped portion 91 (see FIG. 4).

  On the other hand, in the first embodiment, as shown in FIG. 5 (b), the glow plug connector 30 has at least the shape of the opening 33 on the front end side of the cap portion 32 changed to the convex portion 40 according to the shape of the pin terminal 14. The corresponding recess 41 is formed. As a result, the glow plug connector 30 having the cap portion 32 having the shape shown in FIG. 5B and the glow plug 1 having the pin terminal 14 having the shape shown in FIG. Has been. In addition, in the example shown in FIG. 5, the rectangular convex part 40 and the recessed part 41 are provided one each, However, These convex parts 40 and recessed parts 41 are good also as a shape provided in multiple numbers along the circumferential direction. . Further, the convex portion 40 and the concave portion 41 are not limited to a rectangular shape, and may have other shapes such as a triangular shape.

  6 to 9 show other examples of the shape of the pin terminal 14 and the shape of the distal end side opening 33 of the cap portion 32 of the glow plug connector 30. FIG.

  In the example shown in FIG. 6, as shown in FIG. 6A, the pin terminal 14 has a triangular shape when viewed from the rear end side. In the glow plug connector 30, as shown in FIG. 6B, at least the shape of the opening 33 on the front end side of the cap portion 32 is triangular according to the shape of the pin terminal 14. Accordingly, the glow plug connector 30 having the cap portion 32 having the shape shown in FIG. 6B and the glow plug 1 having the pin terminal 14 having the shape shown in FIG. 6A can be inserted and removed in a one-to-one correspondence. Has been. The shape is not limited to a triangular shape, and may be a polygonal shape such as a quadrangular shape or a pentagonal shape or an elliptical shape.

  In the example shown in FIG. 7, as shown in FIG. 7A, the pin terminal 14 has a rectangular shape as viewed from the rear end side and protrudes toward a part of the outer periphery of the pin terminal 14 toward the outer peripheral side. It is the shape in which the convex part 60 of the shape was formed. The protruding length that protrudes toward the outside of the convex portion 60 is longer than the rectangular convex portion 40 shown in FIG. On the other hand, in the glow plug connector 30, as shown in FIG. 7B, at least the shape of the opening 33 on the front end side of the cap portion 32 is a shape in which a notch portion 61 is formed according to the shape of the pin terminal 14. ing. As a result, the glow plug connector 30 having the cap portion 32 having the shape shown in FIG. 7B and the glow plug 1 having the pin terminal 14 having the shape shown in FIG. Has been.

  In the example shown in FIG. 8, as shown in FIG. 8A, the shape of the pin terminal 14 when viewed from the rear end side is recessed in a part of the outer periphery of the pin terminal 14 toward the inner peripheral side. A rectangular recess 70 is formed. On the other hand, as shown in FIG. 8B, the glow plug connector 30 has a rectangular convex portion in which at least the shape of the opening 33 on the front end side of the cap portion 32 protrudes inward depending on the shape of the pin terminal 14. 71 is formed. As a result, the glow plug connector 30 having the cap portion 32 having the shape shown in FIG. 8B and the glow plug 1 having the pin terminal 14 having the shape shown in FIG. Has been.

  In the example shown in FIG. 9, as shown in FIG. 9A, the pin terminal 14 has a rectangular shape as viewed from the rear end side, and protrudes toward a part of the outer periphery of the pin terminal 14 toward the outer peripheral side. A single convex portion 80 is formed. On the other hand, as shown in FIG. 9B, the glow plug connector 30 has at least the shape of the cap portion 32 on the tip side so that the concave portions 81 corresponding to the convex portions 80 of the pin terminals 14 are located at positions 180 ° apart from each other. A total of two shapes are formed each. As a result, the glow plug connector 30 having the cap portion 32 having the shape shown in FIG. 9B and the glow plug 1 having the pin terminal 14 having the shape shown in FIG. 9A can be inserted and removed in a one-to-one correspondence. Has been. In this case, the glow plug 1 and the glow plug connector 30 can be fitted at respective positions rotated by 180 °. In this way, by providing only one convex portion 80 and providing a plurality of concave portions 81 along the circumferential direction, the plurality of concave portions 81 can be fitted at a plurality of rotational direction positions. The number of recesses 81 is not limited to two, and may be three or more.

  In the examples shown in FIGS. 5, 7, and 8, the glow plug 1 and the glow plug connector 30 are fitted in a fixed rotational position, that is, for example, in a position where the convex portion 40 and the concave portion 41 are aligned. It is necessary to match. Further, in the example shown in FIG. 6, the glow plug 1 and the glow plug connector 30 can be fitted at respective positions rotated by 120 ° by making the triangular shape of the pin terminal 14 a regular triangle. . The shape of the pin terminal 14 and the shape of the tip end side of the cap portion 32 of the glow plug connector 30 are such that the shape viewed from the rear end side in the direction of the axis C1 (see FIGS. 1 and 2) It is preferable to be symmetric or point symmetric with respect to a point passing through the axis C1. Thereby, it can be made to fit in the some rotation direction position.

  As described above, in the glow plug assembly structure of the first embodiment, the pin terminals 14 protruding from the rear end toward the rear end side of the metal shell 2 are provided for the plurality of types of glow plugs 1. A first type glow plug connector 30 having a cap portion 32 that can be inserted into and removed from only the pin terminal 14 of the first type of glow plug 1 out of a plurality of types of glow plugs 1 is prepared. The first type glow plug connector 30 is assembled to the first type glow plug 1.

  Therefore, even in the case of a plurality of types of glow plugs 1 having the same external shape of the sheathed heater 3 and the metal shell 2 and having different properties of the heating coil and the control coil, it is mistaken for an automobile engine having a conventional electric system. It is possible to prevent erroneous mounting such as attaching a rapid temperature rising type glow plug, and to prevent damage to the glow plug and the engine due to erroneous mounting of the glow plug.

  Further, regarding the plurality of types of glow plugs 1, the shape of the pin terminal 14 protruding from the rear end to the rear end side of the metal shell 2 as viewed from the axial direction is different for each of the plurality of types of glow plugs 1. A first type of glow plug connector 30 including a cap portion 32 having a shape that can be inserted into and removed from only the pin terminal 14 of the first type of glow plug among the plurality of types of glow plugs 1 is prepared. The first-type glow plug connector 30 can be assembled to the glow plug 1. As a result, only the shape of the pin terminal 14 and the cap portion 32 is changed even in the case of a plurality of types of glow plugs 1 having the same external shape of the sheathed heater 3 and the metal shell 2 and having different properties of the heating coil and the control coil. By doing so, it is possible to easily prevent erroneous mounting such as attaching a rapid temperature rising type glow plug to an automobile engine having a conventional electrical system by mistake. Damage can be easily prevented.

  Next, a second embodiment will be described. In the second embodiment, the shape of the insulating ring 13 of the glow plug 1 is changed for each type of the glow plug 1, and the shape of the cap portion 32 of the glow plug connector 30 is changed accordingly. In the second embodiment, only the shapes of the pin terminal 14 and the insulating ring 13 are different from those in the first embodiment, and the description of the other parts is omitted, and the same members as those in the first embodiment. Uses the same sign.

  In the second embodiment, the shape of the cap portion 32 can be, for example, the shape shown in FIGS. 5B to 9B as in the first embodiment described above.

  On the other hand, the pin terminal 14 does not correspond to the shape of the cap portion 32 as in the first embodiment, and the shape when viewed from the rear end side is substantially circular (having a smaller diameter than the inner hole of the cap portion 32). have. On the other hand, the shape of the insulating ring 13 only needs to correspond to the shape of the cap portion 32 so that the glow plug connector 30 and the glow plug 1 can be inserted and removed in a one-to-one correspondence. It can be set as the shape similar to the shape shown in Fig.5 (a)-FIG.9 (a) demonstrated in the pin terminal 14 of 1st Embodiment. In the second embodiment, the cap portion 32 is externally fitted to the insulating ring 13 of the glow plug 1 when the connector terminal 31 is fitted to the pin terminal 14.

  As in the second embodiment, the shape of the insulating ring 13 is made different for each type of the glow plug 1, and the shape of the cap portion 32 of the glow plug connector 30 is changed accordingly, so that the glow plug 1 and the glow plug 1 The connector 30 may be insertable / removable in a one-to-one correspondence. Further, since the above-described glow plug assembly structure can be realized by processing the shape of the insulator 13 and the cap portion 32, which are resin parts, into predetermined shapes, the manufacture thereof is performed as compared with the case of processing metal parts. The process can be simplified.

  Next, a third embodiment will be described. As shown in FIG. 10, in the third embodiment, the shape of the pin terminal 14 of the glow plug 1 is changed for each type of the glow plug 1, and the shape of the connector terminal 31 of the glow plug connector 30 is changed accordingly. To do. In the third embodiment, only the shapes of the connector terminal 31 and the cap portion 32 are different from those in the first embodiment, and the description of the other parts is omitted, and the same members as in the first embodiment. Uses the same sign. In FIG. 10, the cap portion 32 is omitted for the description of the third embodiment.

  In the third embodiment, the shape of the pin terminal 14 can be, for example, the shape shown in FIGS. 5A to 9A as in the first embodiment described above.

  On the other hand, the cap portion 32 (particularly, the front end opening portion 33) does not correspond to the shape of the pin terminal 14 as in the first embodiment, and the shape when viewed from the rear end side is (than the pin terminal 14). It has a substantially circular shape with a large diameter. On the other hand, the shape of the connector terminal 31 only needs to correspond to the shape of the pin terminal 14 so that the glow plug connector 30 and the glow plug 1 can be inserted and removed in a one-to-one correspondence. It can be set as the shape similar to the shape shown in FIG.5 (b)-FIG.9 (b) demonstrated in the front-end | tip part opening 33 of the cap part 32 of 1st Embodiment.

  As in the third embodiment, the shape of the pin terminal 14 is made different for each type of glow plug 1, and the shape of the connector terminal 31 of the glow plug connector 30 is changed accordingly, so that the glow plug 1 and the glow plug 1 The connector 30 may be insertable / removable in a one-to-one correspondence.

  Next, a fourth embodiment will be described. As shown in FIG. 11, in the fourth embodiment, a glow plug connector 130 having a shape different from that of the second embodiment described above is used. In the fourth embodiment, only the shape of the glow plug connector 130 (particularly, the connector terminal 131) is different from that of the second embodiment, and description of other parts is omitted, and the first embodiment. The same symbols are used for the same members. Moreover, in FIG. 11, the cap part 132 is omitted for the description of the fourth embodiment.

  In the fourth embodiment, as shown in FIG. 11, a metal cup portion 135 having a diameter larger than that of the connector terminal 131 is provided on the distal end side of the connector terminal 31 of the glow plug connector 130. The cup portion 135 is externally fitted to the insulating ring 13 of the glow plug 1 when the connector terminal 131 is fitted to the pin terminal 14.

  In the fourth embodiment, the shape of the insulating ring 13 is the same as in the second embodiment described above, for example, with reference to the pin terminal 14 of the first embodiment, as shown in FIGS. The shape shown in a) can be used.

  On the other hand, the cup portion 135 of the glow plug connector 130 only needs to correspond to the shape of the insulating ring 13 so that the glow plug connector 130 and the glow plug 1 can be inserted and removed in a one-to-one correspondence. The shape shown in FIGS. 5B to 9B described in the cap portion 32 of the first embodiment can be used.

  As in the fourth embodiment, the shape of the insulating ring 13 is made different for each type of glow plug 1, and the shape of the cup portion 135 of the glow plug connector 130 is changed accordingly, so that the glow plug 1 and the glow plug are changed. The connector 130 may be insertable / removable in a one-to-one correspondence.

  Next, a fifth embodiment will be described with reference to FIGS. In the fifth embodiment, the diameters of the insulating rings 113 and 213 of the glow plug 1 are made different for each type of the glow plug 1, and the diameter of at least the front end side opening 233 of the cap portion 232 of the glow plug connector 230 is accordingly changed. The configuration is changed. That is, the glow plug 1 shown in FIGS. 12 (a) and 12 (b) uses an insulating ring 113 having a smaller diameter than the glow plug 1 shown in FIGS. 13 (a) and 13 (b). ), The glow plug 1 shown in (b) uses an insulating ring 213 having a diameter larger than that of the insulating ring 113. In this case, as shown in FIG. 12, the glow plug connector 230 having the tip side opening 233 having a diameter corresponding to the insulating ring 113 can be correctly fitted to the glow plug 1 using the insulating ring 113. However, as shown in FIG. 13, the glow plug connector 230 cannot be properly fitted to the glow plug 1 using the insulating ring 213.

  As described above, the diameters of the insulating rings 113 and 213 protruding from the rear end toward the rear end side of the metal shell 2 are made different for each of the plurality of types of glow plugs 1. A first type of glow plug connector 230 having a cap portion 232 having an inner diameter that can be inserted and removed only into the insulating rings 113 and 213 of the type of glow plug 1 is prepared, and the first type of glow plug 1 is provided with the first type of glow plug 1. The plug connector 230 can be assembled. Accordingly, the specifications of the glow plug 1 and the glow plug connector 230 other than the insulation rings 113 and 213 are not changed, and the shape of the insulation rings 113 and 213 is not changed. Only by changing the diameter, even if the sheath heater 3 and the metal shell 2 have the same external shape, and the plurality of types of glow plugs 1 having different properties of the heating coil and the control coil, the conventional electrical system is mistakenly used. It is possible to prevent erroneous mounting such as attaching a rapid temperature rising type glow plug to the engine of a car having the. Therefore, it is possible to easily prevent the glow plug and the engine from being damaged due to the erroneous installation of the glow plug.

  Next, a sixth embodiment will be described with reference to FIGS. In the sixth embodiment, the thickness of the exposed portion of the insulating ring 13 of the glow plug 1 (the thickness of the enlarged diameter portion on the rear end side shown in FIG. 2) is made different for each type of the glow plug 1. Accordingly, the length of the cap portion 332 of the glow plug connector 330 (the length of the portion extending to the tip side from the included connector terminal) is changed. That is, in this case, for example, depending on the type of the glow plug 1, a thin insulating ring 313 as shown in FIG. 14A and a thick insulating ring 413 as shown in FIG. 15A are used. . Accordingly, in the glow plug 1, the height between the exposed surface of the insulating ring 313 and the rear end side of the insulating ring 413 (upper side in FIGS. 14 and 15) and the rear end portion of the pin terminal 14 (h1, shown in FIG. 14) H2) shown in FIG. 15 changes. In other words, when the thick insulating ring 413 is used, the height h2 between the exposed surface and the rear end of the pin terminal 14 is shorter than h1 when the thin insulating ring 313 is used.

  On the other hand, the glow plug connector 330 is configured such that the tip of the cap portion 332 is in contact with the exposed surfaces of the rear ends of the insulating ring 313 and the insulating ring 413 (upper side in FIG. 14) and the length of the cap portion 332. (The length of the portion extending from the enclosing connector terminal to the front end side) is changed according to the above-described h1 and h2. As a result, the glow plug connector 330 for the glow plug 1 using the insulator 31 ring can be fitted to the glow plug 1 using the insulating ring 313 as shown in FIG. As shown in FIG. 15B, the glow plug 1 using the insulating ring 413 cannot be inserted to a predetermined fitting position and cannot be fitted correctly.

  As described above, the thickness of the insulating rings 313 and 413 protruding from the rear end to the rear end side of the metal shell 2 is made different for each of the plurality of types of glow plugs 1. When the glow plug connector 330 is inserted into the first type of glow plug 1 so that the cap portion 332 contacts the insulating rings 313 and 413 of the one type of glow plug 1, the pin terminal 14 and the connector terminal are electrically connected to each other. A first type glow plug connector 330 having a cap portion 332 that can be connected to the first type glow plug 1 is prepared, and the first type glow plug connector 330 is assembled to the first type glow plug 1. Accordingly, the thickness of the insulating rings 313 and 413 is not changed in the glow plug 1 and the glow plug connector 330 without changing specifications other than the insulating rings 313 and 413 and without changing the shape of the insulating rings 313 and 413. Even if the plurality of types of glow plugs 1 having the same external shape of the sheathed heater 3 and the metal shell 2 and having different properties of the heating coil and the control coil are changed only by changing the height, the conventional electric system It is possible to prevent erroneous mounting such as attaching a rapid temperature rising type glow plug to the engine of a car having the. Therefore, it is possible to easily prevent the glow plug and the engine from being damaged due to the erroneous installation of the glow plug.

  As mentioned above, although this invention was described about embodiment, this invention is not limited to each embodiment, Of course, various deformation | transformation are possible. For example, in the above-described embodiment, the central shaft 8 is configured by a single member, but is not limited thereto, and may be formed by joining (welding or the like) a plurality of members. In the above embodiment, the metal glow plug using a sheathed heater has been described. However, the present invention can be applied to a ceramic glow plug using a ceramic heater.

  DESCRIPTION OF SYMBOLS 1 ... Glow plug, 2 ... Metal fitting, 3 ... Seeds heater, 7 ... Seeds tube, 13 ... Insulation ring, 14 ... Pin terminal, 30, 130, 230, 330 ... Glow plug connector, 31 , 131... Connector terminals, 32, 132, 232, 332... Cap portions, 33, 233, 333.

Claims (8)

A glow plug extending in the axial direction,
A rod-shaped heating element;
A cylindrical metal shell surrounding the heating element and holding the heating element;
A connection terminal inserted into the metal shell and connected to the rear end side of the heating element;
An insulator disposed between the connection terminal and the metal shell, and electrically insulating the connection terminal and the metal shell;
A glow plug having
A glow plug connector that connects to the rear end side of the glow plug and electrically connects the glow plug and an external circuit,
A connector terminal extrapolated to the connection terminal of the glow plug and electrically connected to the connection terminal;
A cap portion enclosing the connector terminal;
A glow plug connector having
In the glow plug assembly structure comprising
The plurality of types of glow plugs having the same external shape of the heat generating body and the metal shell and different performance of the heat generator, the connection terminal protruding from the rear end toward the rear end of the metal shell The shape of at least a part of the end or the insulator is made different for each of the plurality of types of glow plugs,
The first type of glow including the connector terminal or the cap portion having a shape that can be inserted into and removed from only the rear end of the connection terminal of the first type of glow plug or the insulator. Prepare the plug connector
The glow plug assembly structure, wherein the first type glow plug connector is assembled to the first type glow plug. The glow plug assembly structure according to claim 1,
For the plurality of types of glow plugs, the shape of the connecting terminal protruding from the rear end to the rear end side of the metal shell or the insulator viewed from the rear end side in the axial direction is plural types. Different for each glow plug,
Of the plurality of types of glow plugs, the first type of glow plug including a connector terminal having a shape that can be inserted into and removed from only the rear end portion of the connection terminal of the first type glow plug or the insulator. Prepare the plug connector
The glow plug assembly structure, wherein the first type glow plug connector is assembled to the first type glow plug. A glow plug assembly structure according to claim 2,
The shape of the rear end portion of the connection terminal or the insulator projecting from the rear end of the metal shell toward the rear end side is symmetrical with respect to a straight line passing through the axis. Or a glow plug assembly structure characterized by being point-symmetric with respect to a point passing through the axis. A glow plug assembly structure according to claim 2 or 3,
The shape of the rear end portion of the connection terminal that protrudes toward the rear end side from the rear end of the metal shell or the insulator viewed from the rear end side in the axial direction is a protrusion that projects partly outward. Glow plug assembly structure characterized by having a shape with a part. A glow plug assembly structure according to claim 2 or 3,
The shape of the rear end portion of the connection terminal or the insulator that protrudes from the rear end of the metal shell toward the rear end side, as viewed from the rear end side in the axial direction, is partially recessed inward. A glow plug assembly structure characterized by having a shape having a recess. A glow plug assembly structure according to claim 2 or 3,
The shape of the rear end portion of the connection terminal or the insulator protruding from the rear end of the metal shell toward the rear end side, as viewed from the rear end side in the axial direction, is a polygonal shape or an elliptical shape. Glow plug assembly structure. The glow plug assembly structure according to claim 1,
The outer diameter of the insulator projecting from the rear end to the rear end side of the metal shell is varied for each of the plurality of types of glow plugs,
Of the plurality of types of glow plugs, preparing the first type of glow plug connector including the cap portion having an inner diameter that can be inserted and removed only in the insulator of the first type of glow plug.
The glow plug assembly structure, wherein the first type glow plug connector is assembled to the first type glow plug. The glow plug assembly structure according to claim 1,
The thickness of the insulator projecting from the rear end to the rear end side of the metal shell is varied for each of the plurality of types of glow plugs,
When the glow plug connector is inserted into the first type of glow plug so that the cap portion comes into contact with the insulator of the first type of glow plug among the plurality of types of glow plugs, the connection Preparing the first type of glow plug connector provided with the cap portion that enables electrical connection between the terminal and the connector terminal,
The glow plug assembly structure, wherein the first type glow plug connector is assembled to the first type glow plug.

Images