JP5968066B2 - Connector and fixing device - Google Patents

Description

  The present invention relates to a connector for supplying electric power to a connector such as a heater, and a fixing device including the connector.

  In general, an electrophotographic image forming apparatus includes a fixing device that fixes a toner image formed on a sheet by an image forming unit to the sheet. One example is a film-type fixing device. The film-type fixing device uses a ceramic heater in which a heating element is provided on a ceramic substrate. In order to supply electric power to the heater, a connector for supplying electric power is connected to the heater.

  In order to prevent poor electrical contact between the heater and the contact terminal of the connector, it is necessary to ensure a predetermined contact pressure for the electrode portion of the heater. Patent Document 1 describes one method for securing a predetermined contact pressure.

Japanese Patent No. 4585668

  By the way, when a reaction force due to the stiffness of the bundled wire generated when the bundled wire connected to the contact terminal that contacts the heater electrode is wound, the contact terminal mounting backlash against the housing of the connector housing the contact terminal The position of the contact terminal is displaced inside. When the contact terminal is displaced, the positional relationship with the electrode portion of the heater is shifted, and in the worst case, the spring contact of the contact terminal may float, and fixing failure due to contact failure may occur. Therefore, a high dimensional accuracy of the parts is required so as to reduce the gap between the parts, and it is necessary to have a configuration that allows a margin of twisting of the bundled wires so that the reaction force of the bundled wires is not applied to the contact terminals. End up.

  In view of the above circumstances, an object of the present invention is to provide a connector that can ensure a good contact pressure between a spring contact and an electrode portion even when the contact terminal changes its position inside the housing by an external force. And

The present invention for solving the above-described problems is provided with a housing and a cross section in which an opening for mounting on a heater having a heating element formed on a substrate is formed in the housing. In a connector having a letter-shaped conductive member, and a contact terminal provided with a spring contact that contacts the electrode portion of the heater in the opening portion, the opening portion of the contact terminal is formed. And a semi-disc-shaped protrusion that supports the heater at a portion facing the spring contact, and the protrusion does not have elasticity as compared with the spring contact, and the opening from the entrance of the opening The distance to the protrusion is approximately the same as the distance from the entrance of the opening to the spring contact.

  According to the present invention, even when the contact terminal changes its position inside the housing by an external force, a good contact pressure is ensured between the spring contact and the electrode portion.

It is sectional drawing which shows the structure of an image forming apparatus provided with the heating apparatus which has a connector which concerns on Example 1 of this invention. FIG. 2 is a cross-sectional view illustrating a configuration of a fixing device. It is a figure which shows the relationship between a heater and a connector. It is a figure which shows the support relationship of a heater and a support member. It is a figure which shows the structure of the contact terminal of a connector. It is a figure which shows the state with which the connector was mounted | worn with the heater. It is sectional drawing which shows the state in which the attitude | position of the contact terminal inclined inside the housing. It is a figure which shows the structure of the heater which concerns on Example 2, and the supporting member which supports this. It is sectional drawing which shows the state with which the connector was mounted | worn with the heater.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described in detail with reference to the drawings. However, since the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are appropriately changed depending on the configuration of the apparatus to which the invention is applied and various conditions, there is no specific description. As long as the scope of the invention is not limited to these, it is not intended.

  FIG. 1 is a cross-sectional view illustrating a configuration of an image forming apparatus 1 including a fixing device 20 having a connector 110 according to a first embodiment of the present invention. The image forming apparatus 1 is an image forming apparatus using an electrophotographic image forming process. As shown in FIG. 1, the image forming apparatus 1 includes an image forming apparatus main body (hereinafter simply referred to as “apparatus main body”) 1A, and an image forming unit for forming an image is formed inside the apparatus main body 1A. An image forming unit 2 is provided. The image forming unit 2 includes a photosensitive drum 3 that is an “image carrier”, a transfer roller 11 that is a “transfer device”, and the like.

  A full-color image forming apparatus (hereinafter referred to as an image forming apparatus) 1 is configured such that a plurality of image forming units 2a, 2b, 2c, and 2d that form toner images of respective colors are detachable. Further, the image forming apparatus 1 is provided with an intermediate transfer belt unit 7 having an intermediate transfer belt 8 that is an intermediate transfer member, and a fixing device 20. Here, each of the image forming units 2a, 2b, 2c, and 2d has photosensitive drums 3a, 3b, 3c, and 3d that are image carriers. Around the photosensitive drums 3a, 3b, 3c, and 3d, charging rollers 5a, 5b, 5c, and 5d as charging means, developing rollers 4a, 4b, 4c, and 4d as developing means, and a cleaning blade 6a as cleaning means , 6b, 6c, 6d. The image forming units 2 a, 2 b, 2 c, and 2 d are arranged in parallel along the intermediate transfer belt 8.

  In each of the image forming units 2a, 2b, 2c, and 2d, the charging rollers 5a, 5b, 5c, and 5d are installed on the outer peripheral surface of the photosensitive drums 3a, 3b, 3c, and 3d, and the surface of the photosensitive drum is uniformly formed. Charges up. The developing rollers 4a, 4b, 4c, and 4d correspond to the electrostatic latent images of the respective colors on the surface of the photosensitive drum formed by exposure from the respective laser exposure units (exposure means) 26a, 26b, 26c, and 26d. Develop with color toner. The developing rollers 4a, 4b, 4c, and 4d are configured to be separated from the photosensitive drums 3a, 3b, 3c, and 3d and stopped from rotating, thereby preventing deterioration of the developer (not shown). That is, the developing rollers 4a, 4b, 4c, and 4d are configured to be in contact with or separated from the photosensitive drums 3a, 3b, 3c, and 3d. The cleaning blades 6a, 6b, 6c and 6d remove the transfer residual toner adhering to the surface of the photosensitive drum after the toner image is transferred.

  The intermediate transfer belt unit 7 includes an intermediate transfer belt 8, a driving roller 9 that stretches the intermediate transfer belt 8, a tension roller 10, primary transfer rollers 11 a, 11 b, 11 c, and 11 d, and a secondary transfer counter roller 12. . The intermediate transfer belt 8 is rotated and conveyed by rotating the driving roller 9 by a belt driving motor (not shown). Primary transfer rollers 11a, 11b, 11c, and 11d that form a primary transfer portion together with the photosensitive drums 3a, 3b, 3c, and 3d are located at positions where the intermediate transfer belt 8 is sandwiched together with the photosensitive drums 3a, 3b, 3c, and 3d. Opposite installation.

  Further, a secondary transfer roller 14 that forms a secondary transfer portion 28 together with the secondary transfer counter roller 12 is disposed opposite to the position between the secondary transfer counter roller 12 and the intermediate transfer belt 8. The secondary transfer roller 14 is held by a transfer conveyance unit 13.

  A sheet feeding device 15 that feeds the sheet S to the secondary transfer unit 28 is disposed below the image forming apparatus. The sheet supply device 15 includes a paper feed roller 17 that feeds a sheet S from a paper feed cassette 16 that stores a plurality of sheets S, and a separation roller 18 that is a separation unit. The sheets S stored in the paper feed cassette 16 are pressed against each other as the paper feed roller 17 rotates, and are separated and conveyed one by one by the separation roller 18. The separated sheet S is conveyed to the registration roller pair 19 through the main body sheet feeding conveyance path 27. Thereafter, the sheet S is conveyed to the secondary transfer unit 28 by the registration roller pair 19.

  In the secondary transfer unit 28, a positive bias is applied to the secondary transfer roller 14, whereby a plurality of color toner images on the intermediate transfer belt are secondarily transferred to the conveyed sheet S.

  The fixing device 20 includes a heating unit 21 and a pressure roller 22, and a fixing nip portion as a heating nip portion is formed by the pressure contact between the heating unit 21 and the pressure roller 22. The sheet S carrying the unfixed toner image is conveyed to the fixing nip portion and is nipped and conveyed by the fixing nip portion, whereby the unfixed toner image is heated and fixed on the sheet. The sheet S that has passed through the fixing nip is discharged to a discharge tray 25 by a discharge roller pair 24 installed in the discharge unit 23.

  FIG. 2 is a cross-sectional view illustrating a configuration of the fixing device 20. The fixing device 20 includes a heating unit 21, a pressure roller 22, a conveyance roller pair 30, a sheet conveyance guide unit 31, and an exterior unit 32. The heating unit 21 has a heater 100 (double-sided heater). The heater 100 contacts the inner surface of the film 33. The heating unit 21 includes a support member 106 that supports the heater 100 and a cylindrical film 33 that rotates while being in contact with the heater 100 and the support member 106. The pressure roller 22 that is a pressure member forms a fixing nip portion together with the heater 100 through a cylindrical film 33.

  The film 33 rotates following the pressure roller 22 that is rotated by driving from the outside. When the sheet S carrying the unfixed toner image is conveyed to the contact portion between the heating unit 21 and the pressure roller 22, the toner is fixed to the sheet S by heat and pressure. Thereafter, the sheet S is conveyed from the conveyance roller pair 30 to a discharge unit (not shown).

  FIG. 3A is a cross-sectional view showing a configuration of the heater 100 which is a connector object. FIG. 3B is a plan view showing the configuration of the heater 100. FIG. 3C is a rear view showing the configuration of the heater 100. The heater 100 includes an insulating substrate 101, heating elements 102 (102 b and 102 c) provided on the surface of the insulating substrate 101, electrode portions 103 provided at both ends in the longitudinal direction of the insulating substrate 101 and electrically connected to the heating element 102, Have In addition, the electrode portion 103, the conduction portion 104 that conducts electricity from the electrode portion 103 to the heating element 102, and the protective layer 105 that protects the heating element 102 and the conduction portion 104 are provided on both surfaces of the insulating substrate 101. The insulating substrate 101 is made of a ceramic material, and the protective layer 105 is made of a material such as glass. As shown in FIGS. 3B and 3C, the heating elements 102 have different lengths in the longitudinal direction on the front and back sides in order to accommodate sheets of various sizes.

  FIG. 4A is a perspective view showing a support relationship between the heater 100 and the support member 106. FIG. 4B is an enlarged perspective view showing the configuration of the support member 106 on the side in contact with the film 33. FIG. 4C is an enlarged perspective view showing the configuration of the support member 106 on the supported surface side. 4A and 4B, the support member 106 regulates the rotation trajectory of the film 33 while supporting the heater 100 with the groove portion 106A extending in the longitudinal direction. Further, as shown in FIG. 4C, the support member 106 is formed with a notch 107 so that the electrode portion 103c is exposed on the surface. Therefore, the spring contact of the contact terminal can be contacted also from the surface side of the support member 106.

  FIG. 5A is a side view of the configuration of the contact terminal 120 of the connector 110 as seen from one direction. FIG. 5B is a cross-sectional view of the contact terminal 120. FIG. 5C is a perspective view showing the configuration of the contact terminal 120. FIG. 5D is a cross-sectional view showing the configuration of the connector 110. As shown in FIG. 5D, the connector 110 includes a housing 111, a spring contact 121, and a protrusion 122.

  As shown in FIG. 5A to FIG. 5D, the housing 111 is formed in a U-shaped cross section and has an opening 111 </ b> X that is a “first opening”. The contact terminal 120 is provided inside the housing 111 so that its posture can be changed, is formed in a U-shaped cross section, and has an opening 120 </ b> X that is a “second opening”. A spring contact 121 and a protrusion 122 are formed on the contact terminal 120. Note that the opening 120X and the opening 111X are arranged to communicate with each other.

  The spring contact 121 extends from one of the upper and lower sides of the opening 120X toward the other. That is, the first spring contact 121 (the upper spring contact in each drawing of FIG. 6) (first contact portion), which is one of the spring contacts 121, extends downward from above the opening 120X. A second spring contact 121 (a lower spring contact in each drawing in FIG. 6) (second contact portion), which is one of the spring contacts 121, extends upward from below the opening 120X. The spring contact 121 has elasticity to bend when a load is applied, and the contact portion 125 contacts the electrode portion 103. Here, the spring contact 121 is formed in a semi-annular shape in a sectional view on the tip side, and the curved surface portion is a contact portion 125.

  The protrusion 122 protrudes from one of the upper and lower sides of the opening 120 </ b> X of the housing 111 toward one side, and faces the contact portion 125 of the spring contact 121. The first protrusion 122 (the lower protrusion in each figure in FIG. 6), which is one of the protrusions 122, faces the contact part 125 of the first spring contact 121 and extends from the lower part to the upper part of the opening part 120X. It is formed in a convex shape. A second protrusion 122 (an upper protrusion in each drawing of FIG. 6), which is one of the protrusions 122, faces the contact 125 of the second spring contact 121 and extends from the top to the bottom of the opening 120X. It is formed in a convex shape. The protrusion 122 does not have elasticity compared to the spring contact 121. Here, the protrusion 122 has a contact portion formed in a semi-disc shape. As described above, the opening 120X of the contact terminal 120 is formed, and the lower side that supports the connector (heater) on the portion facing the upper contact portion 125 (lower contact portion 125). The protrusion 122 (upper protrusion 122) is formed.

  The lower spring contact 121 is in contact with the electrode parts 103b and 103d (see FIGS. 3B and 6), and when power is supplied through the conduction parts 104b and 104d, the voltage and the resistance of the heating element 102b are applied. The heating element 102b generates heat with a heat generation amount corresponding to the value. The upper spring contact 121 is in contact with the electrode portions 103c and 103e (see FIG. 3C and FIG. 6), and when power is supplied through the conduction portions 104c and 104e, the voltage and the resistance value of the heating element 102c. The heating element 102c generates heat with a heat generation amount according to the above.

  The controller (see FIG. 1) can arbitrarily change whether the heating element 102b and the heating element 102c simultaneously generate heat by controlling the supply of electric power or only one of the heating elements. The electrode portion 103 b and the electrode portion 103 c are arranged so as to overlap each other on the front and back of the insulating substrate 101, and the electrode portion 103 d and the electrode portion 103 e are arranged so as to overlap each other on the front and back of the insulating substrate 101.

  The contact terminal 120 has a U-shaped cross section, and is made of stainless steel, titanium alloy, or the like, and the surface thereof is plated. In addition, spring contacts 121 are provided above and below the U-shaped opening 120 </ b> X, and have contact portions 125 that contact the electrode portion 103 provided in the heater 100. Four protruding projections 122 (heater fitting portions) are provided on the same plane P connecting the upper and lower contact portions 125. Therefore, the distance from the entrance of the opening 120X (the right end in FIG. 5A) to the lower projection 122 (upper projection 122) is the contact point 125 (lower side) from the entrance of the opening 120X. The distance to the contact portion 125) is substantially the same.

  Further, in the contact terminal 120, the bundle wire 123 is connected to the end opposite to the U-shaped opening 120 </ b> X, and a voltage is applied from the bundle wire 123. As described above, the connector 110 is configured by arranging the contact terminal 120 inside the housing 111, and the housing 111 has a U-shaped cross section like the contact terminal 120. The contact terminal 120 is inserted into the housing 111 from the opposite side of the U-shaped opening of the housing 111, and the housing 111 is provided with a stopper 112 that cannot be removed when the contact terminal 120 is inserted. The contact terminal 120 is supported with a clearance A with respect to the housing 111.

  FIG. 6A is a cross-sectional view showing a configuration in which the connector 110 is attached to the heater 100. FIG. 6B is a cross-sectional view taken along the line P-P in FIG. 6A showing a configuration in which the connector 110 is mounted on the heater 100. FIG. 6C is a side view showing the configuration of the connector 110. As shown in FIG. 6A, the support member 106 that supports the heater 100 is engaged with the opening 120 </ b> X formed in the contact terminal 120 of the housing 111 of the connector 110.

  The support member 106 that supports the heater 100 abuts against and engages with an abutting portion 124 formed at the back of the opening 120X of the contact terminal 120 of the connector 110. At this time, the contact portion 125 of the spring contact 121 contacts the upper and lower electrode portions 103 provided in the planar heater 100 with a predetermined contact pressure. The protrusion 122 of the contact terminal 120 contacts the support member 106 on the same plane P connecting the upper and lower contact portions 125.

  Specifically, it is as follows. When a connector is attached to the support member 106 that supports the heater 100 provided with the electrode portion 103, the protrusion 122 contacts the support member 106 when the contact portion 125 of the spring contact 121 contacts the electrode portion 103. To do.

  Here, the connector is attached to the support member 106 where the first electrode portion 103 is exposed from the front surface and the second electrode portion 103 is exposed from the back surface. In this case, the first spring contact 121 contacts the first electrode portion 103 from above and the first protrusion 122 contacts the support member 106 from below. The second spring contact 121 contacts the second electrode portion 103 from below and the second protrusion 122 contacts the support member 106 from above. The first protrusion 122 and the second protrusion 122 sandwich the support member 106.

  FIG. 7 is a cross-sectional view showing a state in which the posture of the contact terminal 120 is inclined inside the housing 111. As shown in FIG. 7, when an external force F such as a reaction force generated when the bundled wire 123 provided on the contact terminal 120 is wound around is applied to the contact terminal 120 (downward in the figure), the contact terminal 120 protrudes. The inside of the housing 111 is swung around the portion 122 as a fulcrum. At this time, since the support member 106 holding the contact terminal 120 and the heater 100 is in contact with the contact portion 125 on the same plane P, the contact terminal 120 swings around the contact portion 125 without being twisted.

  Therefore, the displacement amount of the spring contact 121 does not change, and the contact pressure does not change. Therefore, it is possible to prevent the contact portion 125 from being lifted and not contacting the electrode portion 103. Here, the same effect can be obtained even when the protruding portion 122 is in direct contact with the heater 100 instead of the support member 106 on the same plane P as the contact portion 125.

  FIG. 8A is a perspective view illustrating the configuration of the heater 140 to which the connector 210 according to the second embodiment is mounted and the support member 106 that supports the heater 140. FIG. 8B is a perspective view showing the configuration of the support member 106 on the side in contact with the film 33. FIG. 8C is a perspective view showing a configuration of the support member 106 on the supported surface side. Among the configurations of the second embodiment, the same reference numerals are used for the same configurations and effects as those of the first embodiment, and the description thereof is omitted as appropriate. The configuration of the second embodiment is different from the configuration of the first embodiment in the following points.

  While the first embodiment is a connector for a double-sided heating heater in which heating elements are formed on both sides of the heater substrate, the heating element 102 and the electrode portion 103 are provided only on one side of the heater substrate. It is a connector for a heater (hereinafter referred to as a single-sided heater 140) provided. The support relationship between the single-sided heater 140 and the support member 106 will be described with reference to FIG.

  As shown in FIG. 8A, the support member 106 supports the single-sided heater 140. As shown in FIG. 8B, the support member 106 supports the single-sided heater 140 with the longitudinal groove 106 </ b> A and regulates the rotation trajectory of the film 33. A spacer 132 is provided on the surface of the support member 106 on the side where the heating element 102 is provided. As shown in FIG. 8C, the support member 106 is formed with a notch 107. Due to the notch 107, the electrode portion 103 is exposed. The heating element 102 and the electrode portion 103 may be on the same surface, and the spacer 132 may be provided on the surface opposite to the heating element 102 and the electrode portion 103.

  FIG. 9A is a cross-sectional view showing a configuration in which the connector 210 is mounted on the single-sided heater 140. As shown in FIG. 9A, in the connector 210, the opening 220 </ b> X of the contact terminal 220 inside the housing 111 is engaged with the single-sided heater 140. .

  The spring contact 121 extends downward from above the opening 220X. Specifically, the spring contact 121 is attached to the outer surface of the upper portion of the contact terminal 220 at the base end, and the contact portion enters the opening 220X and extends downward. The contact portion 125 of the spring contact 121 described above comes into contact with the electrode portion 103 provided on the single-sided heater 140.

  The protruding portion 122 faces the contact portion 125 of the spring contact 121 and extends from the lower portion to the upper portion of the opening 220X. Then, the protrusion 122 comes into contact with the spacer 132 attached to the support member 106. When the connector is attached to the support member 106 where the electrode portion 103 is exposed from the notch, the spring contact 121 comes into contact with the electrode portion 103 from above with a predetermined contact pressure, and the protrusion 122 is supported via the spacer 132. It contacts the member 106 from below.

  With the configuration described above, even when the contact terminal 120 receives an external force, the contact portion 125 positioned on the opposite side of the protrusion 122 does not drop from the initial contact pressure. Even if the contact terminal 220 is moved by receiving an external force in the opposite direction, the contact pressure does not change because the contact terminal 220 only swings around the protrusion 122.

  FIG. 9B is a cross-sectional view showing a modification of the second embodiment. As shown in FIG. 9B, the contact terminal 320 of the modified example has a U-shaped cross section, and has a protrusion 122 that contacts the support member 106 from above and below the opening 320X.

  The contact terminal 320 has a protrusion 122 that protrudes from the lower part of the opening 320X toward the upper part, and a protrusion 122 that protrudes from the upper part of the opening 320X toward the lower part. Both the protrusions 122 are set at positions facing each other. On the same plane P connecting the upper and lower protrusions 122, a spring contact 121 having a contact part 125 that contacts the electrode part 103 provided on the single-sided heater 140 is provided. When the support member 106 supporting the single-sided heater 140 abuts and engages with the abutting portion 124 of the connector 110, the contact portion 125 of the spring contact 121 contacts the electrode portion 103 with a predetermined contact pressure, and the projection 122 is supported. Contact member 106.

  With the above-described configuration, when an external force such as a reaction force generated when the bundled wire 123 provided on the contact terminal 320 is wound is applied to the contact terminal 320, the contact terminal 320 is located near the protrusion 122. The inside of the housing 111 is swung around a fulcrum. Therefore, the contact pressure of the contact portion 125 provided at the position on the same plane P as the projection portion 122 does not change.

  According to the configuration of the first, second, and second modified examples described above, even when the contact terminals 120, 220, and 320 are changed in posture inside the housing 111 by an external force, the spring contact 121 and the electrode A good contact pressure is ensured between the portions 103. That is, even when the contact terminal 120 changes its posture inside the housing 111 due to an external force, the contact terminal 120 swings inside the housing 111 using the protrusion 122 as a fulcrum, and between the spring contact 121 and the electrode portion 103, Good contact pressure is ensured.

103 electrode portion 110 connector 111 housing 111X opening (first opening)
120 contact terminal 120X opening (second opening)
121 Spring contact 122 Projection 125 Contact

Claims (4)

A housing;
Is provided in the housing, a conductive member of the cross-section is U-shaped having an opening formed for mounting to a heater heating element is formed on the substrate, of the heater in the opening A contact terminal provided with a spring contact to be in contact with the electrode part;
In a connector having
The contact terminal is the part forming the opening, and the part facing the spring contact has a semi-disc shaped protrusion that supports the heater ,
The protrusion does not have elasticity compared to the spring contact,
The distance from the entrance of the opening to the projection is approximately the same as the distance from the entrance of the opening to the spring contact.   The opening portion of the contact terminal is provided with a second spring contact at a position facing the spring contact, and is a portion forming the opening portion of the contact terminal, and a portion facing the protruding portion The connector according to claim 1, further comprising a second protrusion. The connector according to claim 2, wherein the heater is a heater in which a heating element is formed on both sides of the substrate. A cylindrical film, a heater that contacts the inner surface of the film, a roller that forms a nip portion that sandwiches and conveys the sheet with the heater via the film, and a heater that is attached to the heater and supplies power to the heater A fixing device including:
The connector includes a fixing device which is a connector according to any one of claims 1 to 3.

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