JP6552827B2 - Glow plug and heating device - Google Patents

Description

  The present invention relates to glow plugs and heating devices.

  As a structure of the glow plug, a structure is known in which a heater element is provided on the front end side of the metal shell and a terminal is provided on the rear end side of the metal shell (see, for example, Patent Document 1). The terminal of the glow plug relays electric power supplied from the conductor portion to the heater element by contacting the conductor portion of the connector connected to the power cord. A glow plug that generates heat by energization requires a large current as compared to a spark plug. For this reason, the glow plug terminals are required to have a larger contact area with the conductor portion of the connector than the spark plug terminals.

International Publication No. 2012/046510

  The terminal of the glow plug in Patent Document 1 has the same outer diameter from the portion contacting the conductor portion of the connector to the rear end, so there is a possibility that the connector may be detached from the terminal due to vibration, impact or the like.

  The present invention has been made to solve the above-described problems, and can be realized as the following modes.

(1) According to one aspect of the present invention, a metal shell extending in the axial direction from the front end side to the rear end side; a heater element provided on the front end side of the metal shell for generating heat by energization; It is supplied from the conductor portion to the heater element by connecting the protrusion portion to a connector having a conductor portion and having a protrusion portion projecting along the axial direction from the metal fitting to the rear end side. A glow plug comprising: a terminal for relaying power; In this glow plug, the projecting portion includes a small diameter portion fitted inside the conductor portion; and a large diameter portion positioned on the rear end side from the small diameter portion and having an outer diameter larger than the small diameter portion. The height at which the large diameter portion protrudes in the radial direction from the small diameter portion is 30 μm or more and 400 μm or less, the small diameter portion has a constant outer diameter, and the length of the small diameter portion in the axial direction Is longer than the length of the conductor portion . According to this aspect, the large diameter portion can prevent the conductor portion of the connector from moving to the rear end side rather than the small diameter portion. Therefore, it is possible to prevent the connector from coming off from the terminal. In addition, since the large diameter portion protrudes in the radial direction from the small diameter portion to 30 μm to 400 μm, it is possible to suppress an increase in resistance value when the connector is fitted, and displacement of the connector to the rear end side Can be suppressed.

(2) In the glow plug of the above aspect, the tip end side of the large diameter portion may contact the rear end side of the conductor portion. According to this aspect, rattling of the connector with respect to the terminal can be prevented.

(3) In the glow plug of the above aspect, the small diameter portion may have a constant outer diameter. According to this aspect, the contact area with the conductor portion of the connector can be sufficiently secured in the small diameter portion.

(4) In the glow plug of the above aspect, in the axial direction, the length of the small diameter portion may be longer than the length of the conductor portion. According to this embodiment, a sufficient contact area with the conductor portion can be secured in the small diameter portion.

(5) In the glow plug of the above aspect, the height at which the large diameter portion protrudes in the radial direction from the small diameter portion may be not less than 30 μm and not more than 400 μm. According to this embodiment, it is possible to suppress an increase in the resistance value when the connectors are fitted together, and to suppress a displacement of the connector toward the rear end side.

(6) In the glow plug of the above aspect, the outer diameter of the large diameter portion may be 1.0075 times to 1.1 times the outer diameter of the small diameter portion. According to this embodiment, it is possible to suppress an increase in the resistance value when the connectors are fitted together, and to suppress a displacement of the connector toward the rear end side.

(7) In the glow plug of the above aspect, the outer diameter of the terminal on the distal end side from the small diameter portion may be constant or increase toward the distal end side. According to this aspect, it is possible to prevent the displacement of the connector to the tip end side.

(8) In the glow plug of the above aspect, the terminal is further positioned between the tip end portion located on the tip end side of the terminal and the small diameter portion and the tip portion, and the small diameter portion and the tip portion And a distal large diameter portion having a larger outer diameter. According to this aspect, it is possible to prevent the displacement of the connector to the tip end side.

(9) In the glow plug of the above aspect, the projecting portion may further include a rear end portion located closer to the rear end than the large diameter portion and having an outer diameter smaller than the large diameter portion. According to this embodiment, smooth mounting of the connector to the small diameter portion can be realized.

(10) In the glow plug of the above aspect, the large diameter portion may constitute an end portion of the terminal on the rear end side. According to this aspect, the material of the terminal can be reduced as compared with the case where the large diameter portion is not the end of the terminal.

(11) In the glow plug of the above aspect, an end of the terminal on the rear end side may contact the connector in a state in which the small diameter portion is fitted inside the conductor portion. According to this aspect, the gap formed between the terminal and the connector can be reduced as compared with the case where the end of the terminal is not in contact with the connector. As a result, it is possible to suppress a problem due to water remaining in the gap.

(12) According to one form of this invention, a heating apparatus is provided. The heating device includes the glow plug of the above embodiment, a connector having a conductor portion fitted to the outside of the small diameter portion, and a power supply portion for supplying power to the glow plug through the conductor portion. According to this aspect, the large diameter portion can prevent the conductor portion of the connector from moving to the rear end side rather than the small diameter portion. Therefore, the connector can be prevented from coming off the terminal.

  The present invention can be realized in various forms different from the glow plug and the heating device, and for example, can be realized in the form of a glow plug with a sensor, a terminal of the glow plug, a manufacturing method of manufacturing the glow plug, and the like.

It is an explanatory view showing composition of a heating device. It is an explanatory view showing the appearance composition of a glow plug. It is explanatory drawing which shows the cross-sectional shape of a glow plug. It is an expanded sectional view showing the back end side of a glow plug centering on a terminal. It is explanatory drawing which shows the state in which the connector was connected to the terminal of the glow plug. It is a table | surface which shows the result of the evaluation test which evaluated the length of the small diameter part. It is a table | surface which shows the result of the evaluation test which evaluated the height in a terminal. It is explanatory drawing which shows the state in which the connector was connected to the terminal of the glow plug in the heating apparatus of 2nd Embodiment. It is explanatory drawing which shows the state in which the connector was connected to the terminal of the glow plug in the heating apparatus of 3rd Embodiment. It is explanatory drawing which shows the state in which the connector was connected to the terminal of the glow plug in the heating apparatus of 4th Embodiment. It is explanatory drawing which shows the state in which the connector was connected to the terminal of the glow plug in the heating apparatus of 5th Embodiment. It is explanatory drawing which shows the state in which the connector was connected to the terminal of the glow plug in the heating apparatus of 6th Embodiment. It is explanatory drawing which shows the state in which the connector was connected to the terminal of the glow plug in the heating apparatus of 7th Embodiment. It is explanatory drawing which shows the state in which the connector was connected to the terminal of the glow plug in the heating apparatus of 8th Embodiment.

A. Embodiment A1. Configuration of Heating Device FIG. 1 is an explanatory view showing the configuration of the heating device 10. As shown in FIG. The heating device 10 heats the combustion chamber to assist ignition at the start of an internal combustion engine (not shown) such as a diesel engine. The heating device 10 includes a power supply unit 20, a power cord 30, a connector 40, and a glow plug 50.

  The power supply unit 20 of the heating device 10 supplies power to the glow plug 50 via the power cord 30 and the connector 40. The power supply cord 30 of the heating device 10 is a coated electric wire connecting between the power supply unit 20 and the connector 40. The connector 40 of the heating apparatus 10 relays the power supplied from the power supply unit 20 to the glow plug 50 by fitting with the glow plug 50. The glow plug 50 of the heating device 10 generates heat based on the power supplied through the connector 40.

  FIG. 2 is an explanatory view showing the appearance of the glow plug 50. As shown in FIG. FIG. 3 is an explanatory view showing the cross-sectional shape of the glow plug 50. As shown in FIG. In the description of the present embodiment, the lower side of the glow plug 50 in FIG. 2 is referred to as the “tip side”, and the upper side of FIG. 2 is referred to as the “rear end”. The XYZ axes in FIG. 2 have an X axis, a Y axis, and a Z axis as three space axes orthogonal to one another. In the present embodiment, the Z axis is an axis along the axis AL of the glow plug 50. Of the X-axis directions along the X-axis, the + X-axis direction is the direction from the front of the paper to the back of the paper, and the -X-axis direction is the opposite direction to the + X-axis. Of the Y-axis directions along the Y-axis, the + Y-axis direction is the direction from the right side to the left side of the sheet, and the -Y-axis direction is the opposite direction to the + Y-axis direction. Among the Z-axis directions (axial directions) along the Z-axis, the + Z-axis direction is a direction from the tip end side toward the rear end side, and the -Z-axis direction is the opposite direction to the + Z-axis direction. The XYZ axes in FIG. 2 correspond to the XYZ axes in the other drawings.

  The glow plug 50 includes a terminal 100, a middle shaft 200, an insulating member 300, a metal shell 500, and a heater element 800. In the present embodiment, the axis AL of the glow plug 50 is also an axis of each member such as the terminal 100, the middle shaft 200, the insulating member 300, the metal shell 500, and the heater element 800.

  The terminal 100 of the glow plug 50 is a conductor configured to be connectable to the connector 40. In the present embodiment, the terminal 100 is made of metal (for example, carbon steel (SUM24L, SWCH10R), brass (C3604BD) or the like). In the present embodiment, the surface of the terminal 100 is plated (for example, at least one of tin (Sn), copper (Cu), nickel (Ni), silver (Ag), and the like). Details of the terminal 100 will be described later.

  The center shaft 200 of the glow plug 50 is a rod-like conductor extending in the axial direction from the front end side (−Z axis direction) to the rear end side (+ Z axis direction). In the present embodiment, the center shaft 200 is made of metal (for example, stainless steel or the like). The rear end side of the center shaft 200 is inserted into the terminal 100. The front end side of the center shaft 200 is press-fit to the rear end side of the heater element 800.

  The metal shell 500 of the glow plug 50 is a cylindrical conductor extending around the axis AL. In the present embodiment, the metal shell 500 is made of metal (for example, carbon steel). In the present embodiment, the surface of the metal shell 500 is plated (for example, chromium (Cr), zinc (Zn), nickel (Ni), zinc-nickel alloy, etc.)). The metal shell 500 includes a shaft hole 510, a tool engaging portion 520, and a male screw portion 540.

  The axial hole 510 of the metal shell 500 is a through hole extending around the axis AL. The inner diameter of the shaft hole 510 is larger than the outer diameter of the middle shaft 200. Inside the shaft hole 510, the middle shaft 200 is held on the axis AL. A gap that electrically insulates the shaft hole 510 and the middle shaft 200 is formed between the shaft hole 510 and the middle shaft 200. In the present embodiment, a press-fit portion 514 into which the heater element 800 is press-fitted is formed on the tip side of the shaft hole 510. In the present embodiment, the middle shaft 200 is held on the rear end side of the shaft hole 510 via a cylindrical insulating member 300.

  The tool engagement portion 520 of the metal shell 500 is configured to be engageable with a tool (not shown) used for attaching and detaching the glow plug 50. The external thread portion 540 of the metal shell 500 is configured to be fixable to an internal thread formed in an internal combustion engine (not shown). In the present embodiment, the male screw portion 540 is located on the tip side of the tool engagement portion 520.

  The heater element 800 of the glow plug 50 is a heating element (heating device) that generates heat by energization. In the present embodiment, the heater element 800 is a sheath heater in which a heating coil made of a conductive material is disposed inside the sheath tube. In another embodiment, heater element 800 may be a ceramic heater comprised of a ceramic composition.

  FIG. 4 is an enlarged cross-sectional view showing the rear end side of the glow plug 50 with the terminal 100 in the center. FIG. 5 is an explanatory view showing a state in which the connector 40 is connected to the terminal 100 of the glow plug 50. As shown in FIG. The terminal 100 of the glow plug 50 has a rear end portion 110, a large diameter portion 130, a small diameter portion 150, a tip side large diameter portion 170, a tip portion 180, and an axial hole 190. The rear end portion 110, the large diameter portion 130, and the small diameter portion 150 constitute a protruding portion that protrudes along the axial direction from the metal shell 500 to the rear end side.

  The connector 40 connected to the terminal 100 includes a main body portion 42 and a conductor portion 44. The main body 42 of the connector 40 is made of an electrically insulating resin and covers at least a part of the terminal 100. In the present embodiment, the main body portion 42 has a tubular shape whose one end is closed, and covers the rear end portion 110 of the terminal 100 to a part of the distal end portion 180. In the present embodiment, the main body portion 42 forms a gap between the rear end portion 110, the large diameter portion 130, the small diameter portion 150, and the front end portion 180, and fits into the front large diameter portion 170. The conductor portion 44 of the connector 40 is a metal conductor provided on the inner side of the main body portion 42, and is configured to be able to be fitted to the outer side of the small diameter portion 150 of the terminal 100. The conductor portion 44 is electrically connected to the power supply cord 30 inside the main body portion 42. In the present embodiment, the conductor portion 44 has a cylindrical shape that fits on the outer side of the small diameter portion 150 of the terminal 100, and is notched on the side surface so that it can go over the large diameter portion 130 by plastic deformation in the radial direction. Is formed.

  The rear end portion 110 of the terminal 100 is located on the rear end side from the large diameter portion 130 and constitutes the end portion of the terminal 100 on the rear end side. The rear end portion 110 has an outer diameter smaller than that of the large diameter portion 130.

  The large-diameter portion 130 of the terminal 100 is located on the rear end side from the small-diameter portion 150 and has an outer diameter D2 larger than the outer diameter D1 of the small-diameter portion 150. In the present embodiment, the outer diameter D2 of the large diameter portion 130 is not less than 1.0075 times and not more than 1.1 times the outer diameter D1 of the small diameter portion 150. In the present embodiment, the height Hd at which the large diameter portion 130 protrudes in the radial direction from the small diameter portion 150 is not less than 30 μm and not more than 400 μm. In the present embodiment, the distal end side of the large diameter portion 130 contacts the rear end side of the conductor portion 44 in a state where the connector 40 is connected to the terminal 100.

  The small diameter portion 150 of the terminal 100 is located on the tip end side of the large diameter portion 130 and is configured to be able to fit inside the conductor portion 44 of the connector 40. In the present embodiment, the small diameter portion 150 has a cylindrical shape. The outer diameter D1 of the small diameter portion 150 is substantially constant from the front end side to the rear end side. In the present embodiment, in the axial direction, the length L1 of the small diameter portion 150 is longer than the length of the conductor portion 44.

  The distal end side large diameter portion 170 of the terminal 100 is located between the small diameter portion 150 and the distal end portion 180 and has a larger outer diameter than the small diameter portion 150 and the distal end portion 180. In the present embodiment, the distal end-side large-diameter portion 170 is configured to be able to fit inside the main body portion 42 of the connector 40.

  The distal end portion 180 of the terminal 100 is located on the distal end side with respect to the distal end side large diameter portion 170 and constitutes an end portion of the terminal 100 on the distal end side. The distal end portion 180 has an outer diameter smaller than that of the distal end side large diameter portion 170. In the present embodiment, an axial hole 190 is formed inside the distal end portion 180, and the distal end portion 180 is fixed to the middle shaft 200 inserted into the axial hole 190 by caulking fixation that is compressed from the outside to the inside. It is done. In the present embodiment, the front end portion 180 is located closer to the rear end than the insulating member 300 and the metal shell 500. In other embodiments, the distal end portion 180 may be inserted inside the insulating member 300 and the metal shell 500.

  The shaft hole 190 of the terminal 100 is a hole formed around the axis line AL from the front end side to the rear end side of the terminal 100. The rear end side of the middle shaft 200 is inserted into the shaft hole 190. In the present embodiment, the axial hole 190 is formed from the distal end portion 180 to the distal end side large diameter portion 170. In other embodiments, the axial hole 190 may be formed from the tip 180 to the small diameter portion 150.

A2. Evaluation Test As one of the evaluation tests, the tester prepared a glow plug connected with a connector as a sample, and conducted a vibration test based on Japanese Industrial Standard JIS-D-1601: 1995 on each sample. The vibration conditions in this vibration test are 4 types, D types, and stage 90.

The samples used in this vibration test are as follows.
Sample A1: The first assembly of the connector 40 to the glow plug 50 Sample A2: The assembly of the connector 40 repeated 20 times with respect to the glow plug 50 Sample A3: Glow plug having a terminal on which the large diameter portion 130 is not formed (The same as the glow plug 50 except that the large diameter portion 130 is not formed.) The connector 40 is assembled for the first time Sample A4: The assembly of the connector 40 is repeated 20 times with respect to the same glow plug as the sample A3.

The results of this vibration test are as follows.
Sample A1: The displacement of the connector relative to the terminal before and after the test is 1 mm or less in the axial direction (◎)
Sample A2: Misalignment of the connector with respect to the terminal before and after the test exceeds 1 mm to the tip side (○)
Sample A3: The displacement of the connector relative to the terminal before and after the test is 1 mm or less in the axial direction (◎)
Sample A4: Misalignment of the connector with respect to the terminal before and after the test exceeds 1 mm to the rear end (×)

  According to the result of the vibration test, it can be understood that the large diameter portion 130 can suppress the positional deviation of the connector 40 to the rear end side.

  FIG. 6 is a table showing the results of an evaluation test in which the length L1 of the small diameter portion 150 is evaluated. In the evaluation test of FIG. 6, the tester prepared a plurality of terminals with different lengths L1 of the small diameter portion 150 as samples. In each sample used in the evaluation test of FIG. 6, the outer diameter D1 is 4 mm, and the height Hd is 200 μm. Aside from these samples, the examiner prepared a sample with "relief" as a comparison sample. In the sample having the “relief”, the outer diameter of the portion corresponding to the small diameter portion 150 repeatedly changes between the outer diameter D1 and the outer diameter D2 from the front end side to the rear end side. An undulation is formed on the terminal, and the constant diameter is a terminal which is not continuous in the axial direction.

  The tester individually measured each resistance value of the terminal and the connector, and fitted the connector to the terminal to measure the resistance value between the terminal and the connector. Thereafter, the tester calculated the amount of increase in resistance value by fitting the connector to the terminal. In the connector 40 used for the evaluation test of FIG. 6, the length of the conductor portion 44 in the axial direction is 7 mm.

  According to the evaluation test of FIG. 6, it can be understood that the increase in the resistance value when the connector is fitted can be suppressed by the fact that the outer diameter of the small diameter portion 150 is constant. Further, it can be seen that the increase in the resistance value when the connector is fitted can be further suppressed by the fact that the length L1 of the small diameter portion 150 is longer than the length of the conductor portion 44 in the axial direction.

  FIG. 7 is a table showing the results of an evaluation test in which the height Hd of the terminal 100 is evaluated. In the evaluation test of FIG. 7, the tester prepared a plurality of terminals 100 having different heights Hd as samples. In each sample used in the evaluation test of FIG. 7, the outer diameter D1 is 4 mm, and the length L1 is 7 mm.

  The tester evaluated the resistance value of each sample in the same manner as the evaluation test of FIG. Moreover, the tester performed the vibration test on each sample in which the assembly of the connector 40 to the glow plug 50 was repeated 20 times, similarly to the vibration test described above. In the vibration test of FIG. 6, assuming that damage or deformation occurs in the connector 40 by repeatedly assembling the connector 40 to the glow plug 50, the height Hd of the terminal 100 toward the rear end of the connector 40 is assumed. The effect of preventing misalignment was evaluated.

  According to the result of the evaluation test of FIG. 7, the height Hd is preferably 400 μm or less from the viewpoint of suppressing an increase in the resistance value when the connector 40 is fitted. Further, from the viewpoint of suppressing the positional deviation of the connector 40 to the rear end side, the height Hd is preferably 30 μ or more. Moreover, as for the outer diameter D2 of the large diameter part 130, it is preferable that they are 1.0075 times or more and 1.1 times or less of the outer diameter D1 of the small diameter part 150 from the result of the evaluation test of FIG.

A3. Effect According to the first embodiment described above, the large-diameter portion 130 can prevent the conductor portion 44 of the connector 40 from moving to the rear end side of the small-diameter portion 150. Therefore, it is possible to prevent the connector 40 from being disconnected from the terminal 100.

  Moreover, since the front end side of the large diameter part 130 contacts the rear end side of the conductor part 44, the rattling of the connector 40 with respect to the terminal 100 can be prevented.

  Further, since the small diameter portion 150 has a constant outer diameter D1, the contact area of the connector 40 with the conductor portion 44 can be sufficiently secured in the small diameter portion 150.

  Further, since the length L1 of the small diameter portion 150 is longer than the length of the conductor portion 44 in the axial direction, a contact area with the conductor portion 44 can be sufficiently secured in the small diameter portion 150.

  Further, since the height Hd at which the large diameter portion 130 protrudes in the radial direction from the small diameter portion 150 is 30 μm or more and 400 μm or less, an increase in resistance value when the connector 40 is fitted can be suppressed and Misalignment of the connector 40 can be suppressed. Further, since the outer diameter D2 of the large diameter portion 130 is not less than 1.0075 times and not more than 1.1 times the outer diameter D1 of the small diameter portion 150, an increase in resistance value when the connector 40 is fitted can be suppressed. Misalignment of the connector 40 to the rear end side can be suppressed.

  Further, since the distal end side large diameter portion 170 exists on the distal end side of the small diameter portion 150, the connector 40 can be prevented from being displaced toward the distal end side.

  In addition, since the rear end portion 110 exists on the rear end side from the large diameter portion 130, the connector 40 can be smoothly attached to the small diameter portion 150.

B. Second Embodiment FIG. 8 is an explanatory diagram showing a state in which a connector 40B is connected to a terminal 100B of a glow plug 50B in a heating apparatus 10B of a second embodiment. The heating device 10B of the second embodiment is the same as the heating device 10 of the first embodiment, except that the connector 40B and the glow plug 50B are provided instead of the connector 40 and the glow plug 50.

  The glow plug 50B of the second embodiment is the same as the glow plug 50 of the first embodiment, except that the terminal 100B is provided instead of the terminal 100. The terminal 100B of the second embodiment is the same as the terminal 100 of the first embodiment, except that the distal end side large diameter portion 170 is not provided. In the terminal 100 </ b> B, the distal end portion 180 is located on the distal end side with respect to the small diameter portion 150. In the present embodiment, the outer diameter of the distal end portion 180 is larger than the outer diameter D1 of the small diameter portion 150 and is constant. In other embodiments, the outer diameter of the tip 180 may be larger toward the tip.

  The connector 40B of the second embodiment is the same as the connector 40 of the first embodiment except that a main body 42B is provided instead of the main body 42. The main body 42B of the second embodiment is the same as the main body 42 of the first embodiment except that the main body 42B covers from the rear end 110 to the small diameter part 150 of the terminal 100B and does not contact the terminal 100.

  As one of the evaluation tests, the tester prepared a glow plug connected with a connector as a sample, and carried out a vibration test based on Japanese Industrial Standard JIS-D-1601: 1995 on each sample. The vibration conditions in this vibration test are four types, D type, and stage 90.

The samples used in this vibration test are as follows.
Sample B1: The first assembly of the connector 40B to the glow plug 50B Sample B2: The assembly of the connector 40B repeated 20 times with respect to the glow plug 50B Sample B3: Glow plug having a terminal in which the large diameter portion 130 is not formed (The same as glow plug 50B except that large diameter portion 130 is not formed.) First assembled with connector 40B. Sample B4: Assembly with connector 40B repeated 20 times for the same glow plug as sample A3.

The results of this vibration test are as follows.
Sample B1: Misalignment between the terminal and connector before and after the test exceeds 1 mm to the tip side (○)
Sample B2: Misalignment between the terminal and connector before and after the test exceeds 1 mm to the tip side (○)
Sample B3: The positional deviation between the terminal and the connector before and after the test exceeds 1 mm toward the rear end side (×)
Sample B4: The positional deviation between the terminal and the connector before and after the test exceeds 1 mm toward the rear end side (×)

  According to the result of the vibration test, it can be seen that the large-diameter portion 130 can suppress the displacement of the connector 40B toward the rear end side.

  According to the second embodiment described above, similarly to the first embodiment, it is possible to prevent the connector 40B from coming off from the terminal 100B. In addition, according to the second embodiment, since the distal end-side large diameter portion 170 is not provided, the material of the terminal 100E can be suppressed as compared with the first embodiment. Further, according to the second embodiment, since the distal end-side large diameter portion 170 is not provided, the terminal 100E can be reduced in weight as compared with the first embodiment. Further, according to the second embodiment, since the distal end side large diameter portion 170 is not provided, the process of processing the terminal 100E can be simplified as compared with the first embodiment. For example, in the case of header processing, the number of processing steps is It can be reduced. Further, according to the second embodiment, since the distal end side large diameter portion 170 is not provided, it is possible to prevent the connector from being damaged by sagging formed on the distal end side of the distal end side large diameter portion 170 by processing.

C. Third Embodiment FIG. 9 is an explanatory diagram showing a state in which a connector 40C is connected to a terminal 100B of a glow plug 50B in a heating device 10C of a third embodiment. The heating device 10C of the third embodiment is the same as the heating device 10B of the second embodiment except that a connector 40C is provided instead of the connector 40B. The connector 40C of the third embodiment is the same as the connector 40B of the second embodiment except that a main body 42C is provided instead of the main body 42B. The main body 42C of the third embodiment is the same as the main body 42B of the second embodiment except that the small diameter portion 150 contacts the end of the terminal 100B on the rear end side when the small diameter portion 150 is fitted to the conductor 44. It is.

  As one of the evaluation tests, the tester prepared a glow plug connected with a connector as a sample, and carried out a vibration test based on Japanese Industrial Standard JIS-D-1601: 1995 on each sample. The vibration conditions in this vibration test are 4 types, D types, and stage 90.

The samples used in this vibration test are as follows.
Sample C1: Connector 40C assembled for the first time to glow plug 50B Sample C2: Connector 40C assembled to glow plug 50B repeated 20 times

The results of this vibration test are as follows.
Sample C1: Misalignment between the terminal and connector before and after the test is 1 mm or less in the axial direction (()
Sample C2: Misalignment between the terminal and connector before and after the test is 1 mm or less in the axial direction (◎)

  According to the result of the vibration test, it is understood that the positional deviation of the connector 40C to the rear end side can be further suppressed by the end of the terminal 100B on the rear end side contacting the main body 42C of the connector 40C.

  According to the third embodiment described above, in comparison with the second embodiment, it is possible to further prevent the connector 40C from coming off from the terminal 100B. The end of the terminal 100B on the rear end side is in contact with the connector 40C in a state where the small diameter portion 150 is fitted inside the conductor portion 44, so that the end of the terminal is not in contact with the connector. Thus, the gap formed between the terminal 100B and the connector 40C can be reduced. As a result, it is possible to suppress a problem due to water remaining in the gap.

D. Fourth Embodiment FIG. 10 is an explanatory diagram showing a state in which a connector 40D is connected to a terminal 100B of a glow plug 50B in a heating device 10D of a fourth embodiment. The heating device 10D of the fourth embodiment is the same as the heating device 10B of the second embodiment except that a connector 40D is provided instead of the connector 40B. The connector 40D of the fourth embodiment is the same as the connector 40B of the second embodiment except that a main body 42D is provided instead of the main body 42B. The main body portion 42D of the fourth embodiment is the same as the main body portion 42B of the second embodiment except that the main body portion 42D contacts the tip end side of the small diameter portion 150 in a state where the small diameter portion 150 is fitted into the conductor portion 44. In the present embodiment, the main body portion 42D contacts the small diameter portion 150 at the tip end side of the conductor portion 44.

  As one of the evaluation tests, the tester prepared a glow plug connected with a connector as a sample, and carried out a vibration test based on Japanese Industrial Standard JIS-D-1601: 1995 on each sample. The vibration conditions in this vibration test are 4 types, D types, and stage 90.

The samples used in this vibration test are as follows.
Sample D1: The first assembly of the connector 40D to the glow plug 50B Sample D2: The assembly of the connector 40D repeated 20 times with respect to the glow plug 50B

The results of this vibration test are as follows.
Sample D1: The positional deviation between the terminal and the connector before and after the test is 1 mm or less in the axial direction (◎)
Sample D2: The positional deviation between the terminal and the connector before and after the test is 1 mm or less in the axial direction (◎)

  According to the result of the vibration test, it can be seen that the positional deviation of the connector 40D to the rear end side can be further suppressed by the contact of the front end side of the small diameter portion 150 with the main body 42D of the connector 40D.

  According to the fourth embodiment described above, it is possible to further prevent the connector 40D from coming off from the terminal 100B as compared with the second embodiment.

E. Fifth Embodiment FIG. 11 is an explanatory diagram showing a state in which a connector 40E is connected to a terminal 100E of a glow plug 50E in a heating apparatus 10E of a fifth embodiment. The heating device 10E of the fifth embodiment is the same as the heating device 10B of the second embodiment, except that the connector 40E and the glow plug 50E are provided instead of the connector 40B and the glow plug 50B.

  The glow plug 50E of the fifth embodiment is the same as the glow plug 50B of the second embodiment except that the terminal 100E is provided instead of the terminal 100B. The terminal 100E of the fifth embodiment is the same as the terminal 100B of the second embodiment except that it has a rear end 110E instead of the rear end 110. Except for the point that the rear end portion 110E of the terminal 100E extends in the axial direction from the rear end portion 110 of the second embodiment so as to be able to fit into the main body portion 42E of the connector 40E, the second embodiment. Is the same as the rear end portion 110 of FIG.

  The connector 40E of the fifth embodiment is the same as the connector 40B of the second embodiment, except that a main body 42E is provided instead of the main body 42B. The main body portion 42E of the fifth embodiment is the same as the main body portion 42B of the second embodiment, except that the small diameter portion 150 is in contact with the side surface of the rear end portion 110E in a state where the small diameter portion 150 is fitted to the conductor portion 44.

  According to the fifth embodiment described above, similarly to the fourth embodiment, it is possible to prevent the connector 40E from being disconnected from the terminal 100E.

F. 6th Embodiment FIG. 12: is explanatory drawing which shows the state by which the connector 40F was connected to the terminal 100B of the glow plug 50B in the heating apparatus 10F of 6th Embodiment. The heating device 10F of the sixth embodiment is the same as the heating device 10B of the second embodiment except that a connector 40F is provided instead of the connector 40B. The connector 40F of the sixth embodiment is the same as the connector 40B of the second embodiment except that a main body 42F is provided instead of the main body 42B. The main body portion 42F of the fourth embodiment has a cylindrical shape with both ends open, and is similar to the main body portion 42B of the second embodiment except that it covers the side surfaces of the large diameter portion 130 and the small diameter portion 150. According to the sixth embodiment, similarly to the second embodiment, it is possible to prevent the connector 40F from being detached from the terminal 100B.

G. 7th Embodiment FIG. 13: is explanatory drawing which shows the state by which the connector 40G was connected to the terminal 100B of the glow plug 50B in the heating apparatus 10G of 7th Embodiment. The heating device 10G of the seventh embodiment is the same as the heating device 10B of the second embodiment except that a connector 40G is provided instead of the connector 40B. The connector 40G of the seventh embodiment is the same as the connector 40B of the second embodiment except that a main body 42G is provided instead of the main body 42B. The main body 42G of the seventh embodiment is the same as the main body 42B of the second embodiment except that it covers the entire terminal 100B and the rear end side of the metal shell 500 and fits on the rear end side of the metal shell 500. It is. In the present embodiment, the main body portion 42G fits between the tool engaging portion 520 and the male screw portion 540 in the metal shell 500. According to the seventh embodiment, similarly to the fourth embodiment, it is possible to prevent the connector 40G from coming off from the terminal 100B.

H. Eighth Embodiment FIG. 14 is an explanatory view showing a state in which a connector 40B is connected to a terminal 100H of a glow plug 50H in a heating device 10H according to an eighth embodiment. The heating device 10H of the eighth embodiment is the same as the heating device 10B of the second embodiment, except that a glow plug 50H is provided instead of the glow plug 50B. The glow plug 50H of the eighth embodiment is the same as the glow plug 50B of the second embodiment except that the terminal 100H is provided instead of the terminal 100B. The terminal 100H of the eighth embodiment is the same as the terminal 100B of the second embodiment except that the large diameter portion 130 constitutes the end of the terminal 100H on the rear end side and does not have the rear end 110. According to the eighth embodiment, similarly to the second embodiment, the connector 40B can be prevented from coming off from the terminal 100H. Further, the material of the terminal 100H can be reduced as compared with the case where the large diameter portion 130 is not an end portion of the terminal 100H.

I. Other Embodiments The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, among the technical features in the embodiments, examples, and modifications, those corresponding to the technical features in each embodiment described in the summary section of the invention are for solving some or all of the above-described problems. Alternatively, in order to achieve part or all of the above-described effects, replacement and combination can be performed as appropriate. Further, technical features that are not described as essential in the present specification can be appropriately deleted. For example, the distal end side of the large diameter portion 130 in the terminal 100 may not contact the rear end side of the conductor portion 44 in a state where the connector 40 is connected to the terminal 100. Further, the large-diameter portion 130 of the terminal 100 may contact the main body portion 42 of the connector 40 in a state where the connector 40 is connected to the terminal 100.

Reference Signs List 10, 10B to 10H: heating device 20: power supply unit 30: power cord 40, 40B to 40G: connector 42, 42B to 42G: main body portion 44: conductor portion 50, 50B, 50E, 50H: glow plug 100, 100B, 100E, 100H ... terminals 110, 110E ... rear end portion (protruding portion)
130 ... Large diameter part (protruding part)
150 ... Small diameter part (protrusion part)
170 ... tip end side large diameter section 180 ... tip section 190 ... axial hole 200 ... middle shaft 300 ... insulating member 500 ... main metal fitting 510 ... axial hole 514 ... press fit portion 520 ... tool engagement portion 540 ... male screw portion 800 ... heater element

Claims (9)

A metal shell extending in the axial direction from the front end side to the rear end side;
A heater element provided on the front end side of the metal shell for generating heat by energization;
Supplying from the conductor part to the heater element by connecting the protrusion part to a connector having a conductor part, having a protrusion part protruding along the axial direction from the metal shell to the rear end side A glow plug comprising a terminal for relaying the generated power,
The protrusion is
A small diameter portion fitted inside the conductor portion;
A large diameter portion located on the rear end side from the small diameter portion and having an outer diameter larger than the small diameter portion;
The height at which the large diameter portion protrudes in the radial direction from the small diameter portion is 30 μm or more and 400 μm or less,
The small diameter portion has a constant outer diameter,
In the axial direction, the length of the small diameter portion is longer than the length of the conductor portion .   The glow plug according to claim 1, wherein the leading end side of the large diameter portion contacts the rear end side of the conductor portion. The outer diameter of the large diameter portion is less 1.1 times 1.0075 times the outer diameter of the small diameter portion, the glow plug according to claim 1 or claim 2. The glow plug according to any one of claims 1 to 3 , wherein an outer diameter of the terminal on the distal end side from the small diameter portion is constant or increases toward the distal end side. A glow plug according to any one of claims 1 to 3 , wherein
The terminal is further
A tip portion located on the tip side of the terminal;
A glow plug comprising: a tip side large diameter portion located between the small diameter portion and the tip portion and having an outer diameter larger than the small diameter portion and the tip portion. The said protrusion part is further located in the said rear end side from the said large diameter part, The rear end part which has an outer diameter smaller than the said large diameter part is included in any one of Claim 1-5. The glow plug described. The glow plug according to any one of claims 1 to 5 , wherein the large diameter portion constitutes an end of the terminal on the rear end side. The end of the said terminal in the said back end side contacts the said connector in the state which the said small diameter part fitted inside the said conductor part, The connector as described in any one of Claim 1 to 7 Glow plug. A glow plug according to any one of claims 1 to 8 ;
A connector having a conductor portion fitted to the outside of the small diameter portion;
A power supply unit for supplying power to the glow plug through the conductor portion.

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