Heating unit

Abstract

To provide a heating unit capable of improving the positional accuracy of a connector with respect to a heater.SOLUTION: A heating unit includes a heater 10 having a substrate 11, a resistance heating element supported by the substrate 11, and a power supply terminal 18 electrically connected to the resistance heating element, an endless belt having an inner peripheral surface in contact with the heater 10 and rotating around the heater 10, a holder 20 holding the heater 10, and a connector 50 that is attached to the holder 20 by sandwiching a part of the holder 20 and a part of the heater 10, and in which while attached to the holder 20, a connection terminal 53 is connected to the power supply terminal 18. The connector 50 includes a main body portion 51 sandwiching a part of the holder 20 and a part of the heater 10 while attached to the holder 20, and a claw portion 54 projecting in a direction away from the main body portion 51. The holder 20 has a retaining portion 26 that restricts the movement of the connector 50 to the upstream side in the mounting direction of the connector 50 due to the engagement of the claw portion 54.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a heating unit used in a fixing device of an image forming apparatus or the like.

Background Art

[0002] Conventionally, as a heating unit, a heating unit including a ceramic heater, an endless belt, a holder for supporting the ceramic heater, and a connector for supplying power to the ceramic heater is known (Patent Document 1). In this technology, the heating unit further includes a fixing flange that rotatably supports an end portion of the belt. Further, a locking member for preventing the connector from coming off is disposed on the back surface of the connector. The locking member is a hook arm having one end fixed to the upper surface of the connector and elastically moving up and down. When the connector is mounted, the ceramic heater and the holder are sandwiched, and a claw portion provided on the locking member is locked to a fitting portion provided on the fixing flange.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the conventional configuration, since the fitting portion to which the claw portion of the connector is locked is provided on the fixing flange, which is a member different from the holder, for example, if the positional accuracy between the holder and the fixing flange is low, the connector may move significantly with respect to the holder. If the connector moves significantly with respect to the holder, the positional accuracy of the connector with respect to the heater held by the holder decreases. Therefore, for example, the contact position and contact pressure between the terminals of the heater and the terminals of the connector may vary significantly.

[0005] Therefore, the present invention aims to provide a heating unit that can improve the positional accuracy of the connector relative to the heater. [Means for solving the problem]

[0006] A heating unit for achieving the aforementioned objectives comprises a substrate, a resistive heating element supported by the substrate, a heater having a power supply terminal that is electrically connected to the resistive heating element, an endless belt having an inner circumferential surface that contacts the heater and that rotates around the heater, a holder that holds the heater, and a connector having a connection terminal that is connected to the power supply terminal, which is attached to the holder by sandwiching a part of the holder and a part of the heater, and the connector having a connection terminal that is connected to the power supply terminal when attached to the holder. The connector has a main body that, when mounted on the holder, sandwiches a part of the holder and a part of the heater, and a claw that protrudes away from the main body. The holder has a retaining portion that, when the claw portion engages, restricts the connector from moving upstream in the direction in which it is installed.

[0007] With this configuration, the holder to which the connector is mounted is provided with a retaining portion that restricts the connector from moving upstream in the mounting direction, thereby improving the positional accuracy of the connector relative to the holder. This improves the positional accuracy of the connector relative to the heater held in the holder.

[0008] The connector has an arm portion extending in the mounting direction, one end of which is connected to the main body portion, and the other end of which is an arm portion that is elastically flexible so as to approach the main body portion. The main body portion contacts the side of the holder portion opposite to the heater portion, sandwiching the holder portion and the heater portion. The claw portion is formed on the arm portion, and the retaining portion is positioned to sandwich the arm portion between the main body portion and the connector when the connector is mounted on the holder. The arm portion may be configured to elastically bend and contact the retaining portion when the connector is mounted on the holder.

[0009] According to this design, the restoring force of the arm allows the connector body to be pressed against the side of the holder opposite to the heater. Furthermore, because the connector body is pressed against the side of the holder opposite to the heater, it is possible to suppress the direct force applied from the connector to the heater.

[0010] The holder has a pair of walls facing each other in a direction perpendicular to the mounting direction, and the pair of walls sandwich the connector when the connector is mounted in the holder, and the retaining portion may be configured such that one end is connected to one of the pair of walls and the other end is connected to the other of the pair of walls.

[0011] According to this design, the retaining portion can be supported from both sides by a pair of walls. This ensures the strength of the retaining portion, thereby better restricting the movement of the connector and improving the positional accuracy of the connector relative to the heater.

[0012] The holder may have a configuration that includes a connecting wall portion that connects the downstream ends of a pair of wall portions in the mounting direction.

[0013] According to this, the connecting wall can reinforce the pair of walls. This ensures greater strength in the retaining section supported by the pair of walls, thereby further restricting the movement of the connector and further improving the positional accuracy of the connector relative to the heater.

[0014] The holder may have a restricting surface located upstream of the power supply terminal in the mounting direction, where the main body contacts the connector to restrict it from moving in a direction perpendicular to both the mounting direction and the width direction of the connector.

[0015] According to this, the position of the connector can be restricted by the regulatory surface. This improves the positional accuracy of the connector relative to the heater.

[0016] The restricting surfaces may be configured to be located on both sides of the retaining portion in the width direction.

[0017] According to this design, the position of the connector can be more reliably controlled by a pair of regulating surfaces positioned on both sides of the retaining portion. This improves the positional accuracy of the connector relative to the heater.

[0018] Furthermore, the heating unit for achieving the above-mentioned objectives comprises a substrate, a resistive heating element supported by the substrate, a heater having a power supply terminal that is electrically connected to the resistive heating element, an endless belt having an inner circumferential surface that contacts the heater and that rotates around the heater, a holder that holds the heater, and a connector having a connection terminal that is connected to the power supply terminal, which is attached to the holder by sandwiching a part of the holder and a part of the heater, and the connector having a connection terminal that is connected to the power supply terminal when attached to the holder. The connector has a main body that, when mounted in the holder, sandwiches a part of the holder and a part of the heater. The holder has a restricting surface located upstream of the power supply terminals in the connector mounting direction, which contacts the main body and restricts the connector from moving in a direction perpendicular to both the mounting direction and the connector's width direction.

[0019] With this configuration, the holder on which the connector is mounted is provided with a restricting surface that restricts the movement of the connector, thereby improving the positional accuracy of the connector relative to the holder. This improves the positional accuracy of the connector relative to the heater held in the holder.

[0020] The holder has a configuration having a pair of wall portions and a connecting wall portion, the main body portion has a first main body wall and a second main body wall that face each other in an orthogonal direction perpendicular to both the mounting direction and the direction in which the pair of wall portions face each other, and covers the connecting terminal, and the heating unit may include a connector cover that is attached to the connector and has a cover wall that covers the upstream side of the connecting terminal in the mounting direction.

[0021] According to this, the connection terminal of the connector can be covered so as to be surrounded by the pair of wall portions and the connection wall portion of the holder, the first main body wall and the second main body wall of the main body portion, and the cover wall of the connector cover.

[0022] The cover wall has a through hole through which a cable connected to the connection terminal passes, and the through hole may have a shape along the outer periphery of the cable.

[0023] According to this, the gap between the cover wall and the cable can be reduced.

[0024] The connector cover has a first wall extending in the mounting direction from one end of the cover wall in the orthogonal direction, and a second wall extending in the mounting direction from the other end of the cover wall in the orthogonal direction and sandwiching the main body portion between the first wall. The first wall has a first engaging portion that restricts the connector cover from moving upstream in the mounting direction by engaging with the main body portion, and the second wall has a second engaging portion that restricts the connector cover from moving upstream in the mounting direction by engaging with the main body portion. It may be a configuration having.

[0025] According to this, the connector cover sandwiches the main body portion of the connector between the first wall and the second wall, and restricts the connector cover from moving upstream in the mounting direction by the first engaging portion and the second engaging portion. Therefore, it is possible to prevent the connector cover from coming off the connector.

Effect of the Invention

[0026] According to the present invention, the positional accuracy of the connector with respect to the heater can be improved.

Brief Description of the Drawings

[0027] [Figure 1] It is a cross-sectional view of a heating unit according to an embodiment. [Figure 2] It is a diagram (a) showing a surface on which the resistance heating element of the heater is arranged, a diagram (b) showing the heater and the heat conduction member as viewed from the back side of the heater, and a cross-sectional view (c) of the heating unit cut in the longitudinal direction. [Figure 3] (a) is a perspective view showing one end of the holder in the longitudinal direction and the connector of the first embodiment, and (b) is a perspective view showing the connector mounted on the holder. [Figure 4] This is a cross-sectional view of one longitudinal end of the heater and holder and the connector. [Figure 5] (a) is a perspective view of one end of the holder in the longitudinal direction and the connector as seen from the installation side, and (b) is a perspective view of the connector attached to the holder. [Figure 6] (a) is a perspective view showing the connector with one end of the holder in the longitudinal direction and the connector cover attached, and (b) is a perspective view of the connector and connector cover. [Figure 7] (a) is a perspective view of the connector as seen from the cable side, with one end of the holder in the longitudinal direction and the connector cover attached, and (b) is a perspective view of the connector as seen from the cable side. [Figure 8] This is a cross-sectional view of the connector with one end of the heater and holder in the longitudinal direction and the connector cover attached. [Figure 9] (a) is a perspective view of the connector with the connector cover attached, seen from the second main body wall side, and (b) is a perspective view of the connector and connector cover. [Figure 10] This is a cross-sectional view of XX in Figure 8. [Modes for carrying out the invention]

[0028] Next, the first embodiment of the heating unit will be described in detail with reference to the drawings as appropriate. As shown in Figure 1, the heating unit 1 according to this embodiment is used in fixing devices for image forming apparatuses, devices for transferring foil by heat, and the like. The heating unit 1 comprises a belt 3, a heater 10, a holder 20, a heat conductive member 30, and a pressure roller 40.

[0029] The pressure roller 40 sandwiches the belt 3 between itself and the heater 10. The pressure roller 40 has a cylindrical shaft 41 and a cylindrical roller portion 42. The shaft 41 is made of, for example, metal. The roller portion 42 is made of, for example, rubber. The roller portion 42 covers a part of the shaft 41. The roller portion 42 is in contact with the belt 3. One of the holder 20 and the pressure roller 40 is biased toward the other.

[0030] Belt 3 is an endless belt made of metal or resin. Belt 3 rotates around the heater 10 while being guided by the holder 20. Belt 3 has an outer circumferential surface 3A and an inner circumferential surface 3B. The outer circumferential surface 3A is in contact with the pressure roller 40 or the sheet to be heated. The inner circumferential surface 3B is in contact with the heater 10.

[0031] The heater 10 comprises a substrate 11, a resistive heating element 12 supported by the substrate 11, and a cover 13. The substrate 11 is made of an elongated rectangular plate of ceramic. The heater 10 is a so-called ceramic heater. The resistive heating element 12 is formed on one side of the substrate 11 by printing. As shown in Figure 2(a), in this embodiment, two resistive heating elements 12 are provided. The two resistive heating elements 12 are each long in the longitudinal direction of the heater 10 (hereinafter, the longitudinal direction of the heater 10 is also simply referred to as the "longitudinal direction"), and are arranged parallel to each other and spaced apart in the transverse direction perpendicular to the longitudinal direction. A conductor 19A is connected to one end 12A of each resistive heating element 12, and power supply terminals 18 for supplying power are provided at each end of the conductor 19A.

[0032] The power supply terminal 18 is electrically connected to the resistive heating element 12 via a conductor 19A. The power supply terminal 18 is located at one end 11E in the longitudinal direction of the circuit board 11.

[0033] Furthermore, the other ends 12B of each resistance heating element 12 are connected to each other by a conductor 19B. The number of resistance heating elements 12 is not particularly limited. In addition, the heat distribution in the longitudinal direction may be adjusted by providing resistance heating elements in which the heat generation in the longitudinal center is greater than that in the longitudinal ends, and resistance heating elements in which the heat generation in the longitudinal ends is greater than that in the longitudinal center, and by individually controlling each resistance heating element.

[0034] As shown in Figure 1, the cover 13 covers the resistance heating element 12. The cover 13 is made of, for example, glass. The heater 10 has a nip surface 15 that contacts the inner circumferential surface 3B of the belt 3, and a back surface 16 opposite to the nip surface 15.

[0035] The holder 20 is a member that supports the heater 10. The holder 20 has a support portion 21 and a guide portion 22. The support portion 21 has a plate shape corresponding to the shape of the heater 10. The guide portions 22 are provided at both ends of the support portion 21 in the short direction. Each guide portion 22 has a guide surface 22G along the inner circumferential surface 3B of the belt 3. The guide portion 22 has a plurality of guide ribs 22A arranged in the longitudinal direction.

[0036] The heat conduction member 30 is a member that conducts heat in the longitudinal direction of the heater 10 to equalize the temperature of the heater 10 in the longitudinal direction. The heat conduction member 30 is a sheet-like member and is located between the back surface 16 of the heater 10 and the support portion 21 of the holder 20. When the heating unit 1 sandwiches the sheet, which is the object to be heated, between the belt 3 and the pressure roller 40, the heat conduction member 30 is sandwiched between the heater 10 and the support portion 21. The heat conduction member 30 has a heater side surface 31 that contacts the back surface 16 of the heater 10 and an opposite side surface 32 opposite to the heater side surface 31. The opposite side surface 32 is in contact with the support portion 21.

[0037] The heat conductive member 30 is a member whose thermal conductivity in the planar direction parallel to the heater side surface 31 is greater than the thermal conductivity of the substrate 11 in the planar direction. The material of the heat conductive member 30 is not particularly limited, but for example, a metal with high thermal conductivity such as aluminum, aluminum alloy, or copper can be used.

[0038] As shown in Figures 2(a) and 2(b), one end 12A and the other end 12B of the resistance heating element 12 are located outside the maximum width W1 of the sheet usable by the heating unit 1 in the longitudinal direction, and inside one end 38A and the other end 38B of the heat conductive member 30. In other words, in the longitudinal direction, the length of the heat conductive member 30 is longer than the length of the resistance heating element 12.

[0039] Furthermore, one end 38A and the other end 38B of the heat conductive member 30 are located outside the one end 12A and the other end 12B of the resistance heating element 12, and inside the one end 11A and the other end 11B of the substrate 11, in the longitudinal direction. In other words, in the longitudinal direction, the length of the substrate 11 is longer than the length of the heat conductive member 30. The aforementioned power supply terminal 18 is located at a distance in the longitudinal direction from one end 38A of the heat conductive member 30.

[0040] As shown in Figure 2(c), the support portion 21 of the holder 20 has a first surface 21A, a second surface 21B, and a third surface 21C, which are the surfaces facing the heater 10. The first surface 21A supports the heat conductive member 30 by contacting it. The second surface 21B supports one end 11E of the substrate 11 by contacting it. The third surface 21C supports the other end 11F of the substrate 11 by contacting it. For convenience, the resistance heating element 12, cover 13, and belt 3 are not shown in Figure 2(c).

[0041] The heating unit 1 further includes a connector 50 for supplying electricity to the heater 10. The connector 50 is attached to the holder 20 by sandwiching one longitudinal end, which is part of the holder 20, and one longitudinal end, which is part of the heater 10.

[0042] As shown in Figure 3(a), the connector 50 has a main body portion 51 and an arm portion 52 made of resin or the like, a connection terminal 53 made of a conductive material such as metal, and a claw portion 54.

[0043] The connection terminals 53 are made of an elastic metal plate. The connection terminals 53 corresponding to the positive power supply terminal 18 of the heater 10 and the connection terminals 53 corresponding to the negative power supply terminal 18 of the heater 10 are spaced apart in the longitudinal direction of the heater 10. As shown in Figure 4, the connection terminals 53 are connected to the power supply terminals 18 of the heater 10. Specifically, when the connector 50 is mounted on the holder 20, the connection terminals 53 are connected to the power supply terminals 18.

[0044] The main body portion 51 is the part that sandwiches one longitudinal end of the holder 20 and one longitudinal end of the heater 10 when the connector 50 is attached to the holder 20, and has a base portion 51A and a first extension portion 51B and a second extension portion 51C that extend from the base portion 51A toward the heater 10.

[0045] The first extension 51B has a connection terminal 53. The first extension 51B and the second extension 51C are spaced apart in an orthogonal direction that is perpendicular to both the mounting direction of the connector 50 and the width direction of the connector 50 (see Figure 3(a)). In the orthogonal direction, the first extension 51B (specifically the connection terminal 53) and the second extension 51C sandwich one end of the holder 20 in the longitudinal direction and one end of the heater 10 in the longitudinal direction.

[0046] The connector 50 is attached to one end of the holder 20 in the longitudinal direction, moving from one side of the heater 10 in the short direction to the other side (from right to left in Figure 4). The direction from one side of the heater 10 in the short direction to the other side is the mounting direction of the connector 50. Hereafter, the mounting direction of the connector 50 will also be simply referred to as the "mounting direction". In this embodiment, the width direction of the connector 50 is the same as the longitudinal direction of the heater 10 when the connector 50 is attached to the holder 20.

[0047] As shown in Figure 3(a), the second extension 51C has a groove 51D on the surface facing the first extension 51B. The groove 51D has a shape that is recessed in the orthogonal direction and extends in the mounting direction. The groove 51D is located in the center of the connector 50 in the width direction of the connector 50. The groove 51D receives a projection 21E formed at one end of the holder 20 in the longitudinal direction when the connector 50 is mounted on the holder 20 (see Figure 2). This restricts the longitudinal movement of the connector 50 relative to the holder 20 when the connector 50 is mounted on the holder 20. The projection 21E has a shape that protrudes in the orthogonal direction and extends in the mounting direction (see Figure 5(a)).

[0048] As shown in Figure 4, the arm portion 52 is located on one side of the main body portion 51 in a perpendicular direction and extends in the mounting direction of the connector 50. The arm portion 52 is located in the center of the connector 50 in the width direction of the connector 50 (see Figure 3(a)). The arm portion 52 extends from the tip of the second extension portion 51C in the opposite direction to the first extension portion 51B and bends, extending downstream in the mounting direction with a gap between it and the second extension portion 51C. As a result, one end of the arm portion 52 in the mounting direction is connected to the main body portion 51, and the other end is elastically flexible so as to approach the main body portion 51.

[0049] The arm portion 52 is elastically flexible when the connector 50 is attached to the holder 20 and contacts the retaining portion 26 of the holder 20, which will be described later. At this time, the main body portion 51 is such that the first extension portion 51B and the second extension portion 51C sandwich one end of the holder 20 in the longitudinal direction and one end of the heater 10 in the longitudinal direction, and the second extension portion 51C contacts the fourth surface 21D of the holder 20 opposite to the second surface 21B that supports a portion of the heater 10 in the longitudinal direction.

[0050] The claw portion 54 is formed on the arm portion 52. More specifically, the claw portion 54 is formed to protrude from near the center of the arm portion 52 in the mounting direction, away from the main body portion 51. The upstream surface of the claw portion 54 in the mounting direction is a surface that is substantially perpendicular to the mounting direction, and the downstream surface in the mounting direction is an inclined surface that approaches the arm portion 52 as it moves from the upstream side to the downstream side in the mounting direction.

[0051] As shown in Figures 3(a) and 3(b), the holder 20 further comprises a pair of wall sections 23, a connecting wall section 24, and a support section 25. The pair of wall sections 23, the connecting wall section 24, and the support section 25 are integrally formed at one end of the holder 20 in the longitudinal direction.

[0052] The pair of walls 23 are a pair of walls facing each other in a direction perpendicular to the mounting direction of the connector 50, and in this embodiment, in the longitudinal direction of the heater 10. The pair of walls 23 are provided so as to sandwich the connector 50 when the connector 50 is mounted on the holder 20. In the longitudinal direction of the heater 10, the distance between the pair of walls 23 is slightly greater than the width of the connector 50 (the width of the connector 50). For example, the distance between the pair of walls 23 is about a few tenths of a millimeter greater than the width of the connector 50. The pair of walls 23 consists of a wall 23A located on one side in the longitudinal direction as one of the pair of walls 23, and a wall 23B located on the other side in the longitudinal direction as the other of the pair of walls 23.

[0053] The connecting wall portion 24 is a wall that connects the downstream ends of the pair of wall portions 23 (23A, 23B) in the mounting direction. The connecting wall portion 24 is approximately perpendicular to the mounting direction of the connector 50.

[0054] As shown in Figures 5(a) and (b), the erection section 25 is the upstream end of the pair of wall sections 23 in the mounting direction, and is provided to connect the ends on one side (upper side in Figure 5) in the perpendicular direction. The erection section 25 has a retaining section 26 and a pair of restricting sections 27.

[0055] As shown in Figures 3(b) and 4, the retaining portion 26 is the part that the claw portion 54 of the connector 50 can engage with when the connector 50 is mounted on the holder 20. The retaining portion 26 restricts the connector 50 from moving upstream in the mounting direction when the claw portion 54 engages with it. As shown in Figure 4, when the connector 50 is mounted on the holder 20, the retaining portion 26 is positioned to sandwich the arm portion 52 between the main body portion 51 of the connector 50. As shown in Figure 5(a), one end of the retaining portion 26 in the longitudinal direction is connected to the wall portion 23A via one restricting portion 27(27A), and the other end is connected to the wall portion 23B via the other restricting portion 27(27B).

[0056] The restricting portion 27 consists of a restricting portion 27A located between the retaining portion 26 and the wall portion 23A, and a restricting portion 27B located between the retaining portion 26 and the wall portion 23B. One side of the restricting portion 27 in the orthogonal direction (the upper side in Figure 5) is substantially flush with one side of the retaining portion 26 in the orthogonal direction.

[0057] On the other hand, the restricting portion 27 has a surface on the other side in the orthogonal direction (restricting surface 28, described later) that is closer to the main body 51 of the connector 50 than the surface on the other side in the orthogonal direction of the retaining portion 26 (see Figure 5(b)). The other side of the restricting portion 27 in the orthogonal direction and the other side of the retaining portion 26 in the orthogonal direction are connected by an inclined surface that, in the longitudinal direction, approaches the main body 51 of the connector 50 as it moves outward from the erection portion 25.

[0058] As shown in Figure 4, each restricting portion 27 (only one shown) is located upstream of the power supply terminal 18 in the mounting direction of the connector 50. Each restricting portion 27 has a restricting surface 28. Specifically, the other side of each restricting portion 27 in the orthogonal direction is the restricting surface 28. The restricting surface 28 comes into contact with the main body 51 of the connector 50 when the cable 55 connected to the connector 50 is pulled upward in Figure 4, thereby restricting the connector 50 from moving in the orthogonal direction, in this embodiment, upward in Figure 4.

[0059] As shown in Figure 5(b), the restricting portion 27 is located on both sides of the retaining portion 26 in the longitudinal direction of the heater 10. Therefore, the restricting surfaces 28 formed on each restricting portion 27 are located on both sides of the retaining portion 26 in the longitudinal direction of the heater 10.

[0060] According to the first embodiment described above, since the holder 20 to which the connector 50 is mounted is provided with a retaining portion 26 that restricts the connector 50 from moving upstream in the mounting direction, the positional accuracy of the connector 50 relative to the holder 20 can be improved. This improves the positional accuracy of the connector 50 relative to the heater 10 held in the holder 20. As a result, for example, the contact position and contact pressure between the power supply terminal 18 of the heater 10 and the connection terminal 53 of the connector 50 can be stabilized.

[0061] Furthermore, the arm portion 52 of the connector 50 elastically bends when the connector 50 is mounted on the holder 20 and contacts the retaining portion 26 of the holder 20. As a result, the restoring force of the arm portion 52 can press the main body portion 51 of the connector 50 against the fourth surface 21D of the holder 20 opposite to the heater 10. This suppresses the displacement of the connector 50 relative to the heater 10 due to vibrations when the heating unit 1 is operating, for example, and thus suppresses fluctuations in the contact position and contact pressure between the power supply terminal 18 and the connection terminal 53.

[0062] Furthermore, since the main body 51 of the connector 50 presses against the fourth surface 21D of the holder 20 opposite to the heater 10, it is possible to suppress the direct application of force from the connector 50 to the heater 10. This suppresses, for example, the application of bending stress from the connector 50 to the substrate 11 of the heater 10, thereby suppressing cracks in the resistance heating element 12 that may occur due to bending of the substrate 11.

[0063] Furthermore, since one longitudinal end of the retaining portion 26 is connected to one wall portion 23A and the other end is connected to the other wall portion 23B, the retaining portion 26 can be supported from both sides by the pair of wall portions 23 (23A, 23B). This ensures the strength of the retaining portion 26, thereby further restricting the movement of the connector 50 when the claw portion 54 of the connector 50 engages with the retaining portion 26, and further improving the positional accuracy of the connector 50 relative to the heater 10.

[0064] Furthermore, since the holder 20 has a connecting wall portion 24 that connects the pair of wall portions 23, the pair of wall portions 23 can be reinforced by the connecting wall portion 24. This ensures greater strength of the retaining portion 26 supported by the pair of wall portions 23, thereby further restricting the movement of the connector 50 and further improving the positional accuracy of the connector 50 relative to the heater 10.

[0065] Furthermore, since the holder 20 to which the connector 50 is mounted is provided with a restricting surface 28 that restricts the movement of the connector 50, the positional accuracy of the connector 50 relative to the holder 20 can be improved. Specifically, for example, even if the connector 50 attempts to swing around the area near the part of the holder 20 that is sandwiched by the connector 50, due to the cable 55 connected to the connector 50 being pulled, the main body 51 can restrict the position of the connector 50 relative to the holder 20 by contacting the restricting surface 28. This improves the positional accuracy of the connector 50 relative to the heater 10 held in the holder 20.

[0066] Furthermore, since the restricting surfaces 28 are positioned on both sides of the retaining portion 26, even if the connector 50 attempts to swing as described above, the pair of restricting surfaces 28 positioned on both sides of the retaining portion 26 can more reliably restrict the position of the connector 50. This improves the positional accuracy of the connector 50 relative to the heater 10.

[0067] Next, a second embodiment will be described. In the following, the differences from the first embodiment will be described, and for the same components, the same reference numerals will be used and their descriptions will be omitted as appropriate. As shown in Figures 6(a) and 6(b), the heating unit 1 of the second embodiment further includes a connector cover 60 that is attached to the connector 50.

[0068] As shown in Figure 7(b), the main body 51 of the connector 50 has a first main body wall 511 and a second main body wall 512 which are walls in the orthogonal direction, a third main body wall 513 and a fourth main body wall 514 which are walls in the width direction of the connector 50, and a fifth main body wall 515. The orthogonal direction is the direction perpendicular to both the mounting direction of the connector 50 and the direction in which the pair of walls 23 of the holder 20 face each other. In this embodiment, the direction in which the pair of walls 23 face each other is the same as the width direction of the connector 50 when the connector 50 is mounted on the holder 20.

[0069] As shown in Figure 8, the first main body wall 511 and the second main body wall 512 face each other in orthogonal directions. When viewed from the orthogonal direction, the first main body wall 511 and the second main body wall 512 cover the connection terminal 53. In this embodiment, the arm portion 52 of the connector 50 extends from the downstream end of the first main body wall 511 in the mounting direction.

[0070] The third main wall 513 and the fourth main wall 514 face each other in the width direction of the connector 50 and have a substantially symmetrical shape in the width direction of the connector 50. The third main wall 513 and the fourth main wall 514 have a substantially U-shape that opens toward the downstream side in the mounting direction when viewed from the width direction of the connector 50, and cover a part of the connection terminal 53, specifically the part of the connection terminal 53 excluding the contact portion 53A that is connected to the power supply terminal 18. The contact portion 53A is exposed from the substantially U-shaped opening of the third main wall 513 and the fourth main wall 514 when viewed from the width direction of the connector 50 before it is mounted on the holder 20.

[0071] As shown in Figure 7(b), the fifth main body wall 515 extends in a perpendicular direction and connects the upstream end of the first main body wall 511 in the mounting direction to the upstream end of the second main body wall 512 in the mounting direction. The fifth main body wall 515 is positioned between the third main body wall 513 and the fourth main body wall 514 in the width direction of the connector 50. Having such a fifth main body wall 515 ensures the rigidity of the main body portion 51. The fifth main body wall 515 has a recess 515A at the end closest to the first main body wall 511 in the perpendicular direction, which is recessed from the upstream side to the downstream side in the mounting direction.

[0072] As shown in Figure 6(b), the connector cover 60 has a cover wall 61, a first wall 62, a second wall 63, and a positioning portion 64.

[0073] As shown in Figure 8, the cover wall 61 covers the upstream side of the connector 50 in the mounting direction when the connector cover 60 is attached to the connector 50. More specifically, the cover wall 61 covers the opening formed by the first main wall 511, the second main wall 512, the third main wall 513, and the fourth main wall 514 from the upstream side in the mounting direction (see also Figure 7). As a result, the cover wall 61 covers the upstream side of the connection terminal 53 in the mounting direction when the connector cover 60 is attached to the connector 50.

[0074] As shown in Figures 8 and 7(a), the cover wall 61 has two through holes 65. The through holes 65 are holes through which a cable 55 connected to the connection terminal 53 of the connector 50 passes. The through holes 65 have a shape that follows the outer circumference of the cable 55. More specifically, when viewed from the mounting direction, the through holes 65 have a circular shape that follows the outer circumference of the substantially circular cable 55. In this embodiment, the inner surface of the through hole 65 is in contact with the outer circumference of the cable 55. More specifically, the inner surface of the through hole 65 is in contact with the outer circumference of the cable 55 around its entire circumference.

[0075] As shown in Figure 6(b), the first wall 62 extends from one end of the cover wall 61 in the direction perpendicular to it toward the downstream side in the mounting direction, and the second wall 63 extends from the other end of the cover wall 61 in the direction perpendicular to it toward the downstream side in the mounting direction. When the connector cover 60 is attached to the connector 50, the second wall 63 sandwiches the main body 51 of the connector 50 between itself and the first wall 62.

[0076] The first wall 62 has a pair of first engaging portions 62A and 62B. The first engaging portions 62A and 62B engage with the main body 51 of the connector 50, thereby restricting the movement of the connector cover 60 upstream in the mounting direction. Specifically, the first wall 62 has an arm body 62C that extends downstream in the mounting direction from one end of the cover wall 61 in the orthogonal direction. The first engaging portion 62A protrudes from the tip of the arm body 62C toward one side in the width direction of the connector 50, and the first engaging portion 62B protrudes from the tip of the arm body 62C toward the other side in the width direction of the connector 50.

[0077] The connector 50 has first ribs 56A and second ribs 56B that protrude outward in a perpendicular direction from both ends in the width direction of the first main body wall 511 and extend in the mounting direction. The first ribs 56A and second ribs 56B extend from near the center of the main body 51 in the mounting direction to near the upstream end. As shown in Figure 7(a), when the connector cover 60 is attached to the connector 50, the first wall 62 restricts the movement of the connector cover 60 upstream in the mounting direction by having a first engaging portion 62A engage with the first rib 56A and a first engaging portion 62B engage with the second rib 56B.

[0078] As shown in Figures 9(a) and (b), the second wall 63 has a second engaging portion 63A. The second engaging portion 63A engages with the main body 51 of the connector 50, thereby restricting the movement of the connector cover 60 upstream in the mounting direction. More specifically, the second wall 63 has a pair of extensions 63B extending downstream in the mounting direction from the other end of the cover wall 61 in the direction perpendicular to it. The pair of extensions 63B are spaced apart in the width direction of the connector 50. The second engaging portion 63A is provided to connect the tips of the pair of extensions 63B. The second wall 63 has a substantially U-shape with its downstream end in the mounting direction closed.

[0079] The connector 50 has a second claw portion 57 that protrudes outward in a perpendicular direction from near the center of the second main body wall 512 in the mounting direction. The second claw portion 57 has a surface on the downstream side in the mounting direction that is substantially perpendicular to the mounting direction, and a surface on the upstream side in the mounting direction that is inclined so that it moves away from the second main body wall 512 as it moves from the upstream side to the downstream side in the mounting direction. When the connector cover 60 is attached to the connector 50, the second wall 63 restricts the movement of the connector cover 60 upstream in the mounting direction by the engagement of the second engaging portion 63A with the second claw portion 57.

[0080] The connector cover 60 is made of a heat-resistant resin such as PA66 (polyamide resin) or LCP (liquid crystal polymer). Because heat-resistant resins are relatively hard, they do not easily undergo elastic deformation. Therefore, in order to ensure that the first wall 62 and the second wall 63 can be easily elastically deformed when the connector cover 60 is attached to the connector 50, in this embodiment, the first wall 62 and the second wall 63 are formed in a plate shape and their length in the mounting direction is made sufficiently long. As an example, the length of the first wall 62 and the second wall 63 in the mounting direction is 1.5 times or more longer than the perpendicular distance between the first wall 62 and the second wall 63.

[0081] As shown in Figure 6(b), the positioning portion 64 has a rib shape that protrudes from the downstream side of the cover wall 61 in the mounting direction toward the downstream side in the mounting direction and extends in the width direction of the connector 50. The positioning portion 64 has a recess 64A in the center of the connector 50 in the width direction that is recessed from the downstream side toward the upstream side in the mounting direction. The recess 64A can engage with a recess 515A (see Figure 7(b)) formed in the fifth main wall 515 of the connector 50. When the connector cover 60 is attached to the connector 50, the recess 64A of the positioning portion 64 engages with the recess 515A of the fifth main wall 515, thereby regulating the position of the connector 50 in the width direction and orthogonal direction relative to the connector 50.

[0082] To attach the connector cover 60 to the connector 50, for example, the end of the cable 55 before connecting to the connection terminal 53 is passed through the through hole 65 in the cover wall 61. Then, the end of the cable 55 (electric wire) and the connection terminal 53 are electrically connected. After that, the connector cover 60 is attached to the connector 50 so that the main body 51 is sandwiched between the first wall 62 and the second wall 63, and the first engaging portions 62A and 62B of the first wall 62 are engaged with the ribs 56A and 56B of the main body 51, and the second engaging portion 63A of the second wall 63 is engaged with the second claw portion 57 of the main body 51. In this way, the connector cover 60 can be attached to the connector 50.

[0083] As shown in Figure 10, with the connector 50 mounted on the holder 20, the pair of walls 23 of the holder 20 cover the contact portion 53A of the connection terminal 53 when viewed from the width direction of the connector 50. Also, as shown in Figure 8, the first main body wall 511 and the second main body wall 512 of the connector 50 cover the connection terminal 53, including the contact portion 53A, when viewed from the orthogonal direction. Furthermore, with the connector 50 mounted on the holder 20, the connection wall portion 24 of the holder 20 covers the downstream side in the mounting direction of the connection terminal 53, and the cover wall 61 of the connector cover 60 covers the upstream side in the mounting direction of the connection terminal 53.

[0084] The connection terminal 53 is positioned such that, when the connector 50 with the connector cover 60 attached is mounted on the holder 20, it is housed inside the enclosure formed by the main walls 511-514 of the connector 50, the pair of wall portions 23 and connection wall portion 24 of the holder 20, and the cover wall 61 of the connector cover 60. The main body 51 of the connector 50 and the holder 20 are made of a heat-resistant resin, similar to the connector cover 60.

[0085] According to the second embodiment described above, the pair of wall portions 23 and connecting wall portion 24 of the holder 20, the first body wall 511 and second body wall 512 of the main body portion 51 of the connector 50, and the cover wall 61 of the connector cover 60 can further surround and cover the connection terminal 53 of the connector 50.

[0086] Furthermore, since the through-hole 65 of the cover wall 61 has a shape that follows the outer circumference of the cable 55, the gap between the cover wall 61 and the cable 55 can be reduced. In the second embodiment, since the inner surface of the through-hole 65 is in contact with the outer circumference of the cable 55, the formation of a gap between the cover wall 61 and the cable 55 can be suppressed.

[0087] Furthermore, the connector cover 60 sandwiches the main body 51 of the connector 50 between the first wall 62 and the second wall 63, and the first engaging parts 62A, 62B and the second engaging part 63A restrict the movement of the connector cover 60 upstream in the mounting direction, thereby preventing the connector cover 60 from coming off the connector 50.

[0088] The embodiments have been described above, but the heating unit can be modified as appropriate as shown below.

[0089] In the above embodiment, the restricting surface 28 of the holder 20 was provided on both sides of the retaining portion 26 in the longitudinal direction of the heater 10, but for example, the restricting surface may be provided on only one side of the retaining portion.

[0090] In the above embodiment, the holder 20 had a pair of wall portions 23, a connecting wall portion 24, and a mounting portion 25, but it is not limited to this configuration. For example, referring to Figure 5, the holder may further have a second mounting portion that connects the lower ends of the pair of wall portions 23 in Figure 5, and sandwiches the connector 50 between itself and the mounting portion 25 when the connector 50 is attached to the holder.

[0091] Furthermore, in the above embodiment, the retaining portion 26 was connected to both of the pair of wall portions 23, but for example, the retaining portion may be connected to only one of the pair of wall portions. Also, the holder may be configured without a connecting wall portion, or even without a pair of wall portions.

[0092] In the above embodiment, the connector 50 had a claw portion 54 formed on the arm portion 52, but for example, in a configuration in which the connector does not have an arm portion, the claw portion may protrude directly from the main body portion. Also, there may be multiple claw portions. Furthermore, the holder may be configured so that multiple claw portions can engage with one retaining portion, or it may be configured to have multiple retaining portions corresponding to multiple claw portions.

[0093] In the above embodiment, the mounting direction of the connector 50 was perpendicular to the longitudinal direction of the heater 10, but for example, the mounting direction of the connector may be the same as the longitudinal direction of the heater.

[0094] In the above embodiment, the substrate 11 of the heater 10 was made of an elongated rectangular plate of ceramic, but for example, the substrate of the heater may be made of an elongated rectangular plate of metal such as stainless steel.

[0095] In the above embodiment, the power supply terminal 18 was located at one end of the heater 10 in the longitudinal direction. However, for example, the power supply terminal may be configured such that the positive power supply terminal is located at one end of the heater in the longitudinal direction and the negative power supply terminal is located at the other end of the heater in the longitudinal direction. In this case, the heating unit may be configured to include a first connector attached to one end of the holder in the longitudinal direction and a second connector attached to the other end of the holder in the longitudinal direction.

[0096] In the above embodiment, the power supply terminal 18 and connector 50 of the heater 10 were located on the outside of the belt 3 in the longitudinal direction of the heater 10. However, for example, the power supply terminal and connector of the heater may be located on the inside of the belt in the longitudinal direction of the heater.

[0097] In the above embodiment, the heating unit 1 was equipped with a heat conductive member 30, but for example, the heating unit may be configured without a heat conductive member.

[0098] In the above embodiment, the connector 50 had a main body portion 51 and a claw portion 54, and the holder 20 had a retaining portion 26 and a restricting surface 28. However, for example, the heating unit may have a configuration in which the holder does not have a restricting surface. Alternatively, the heating unit may have a configuration in which the connector has a main body portion, the holder has a restricting surface, and does not have a claw portion or a retaining portion.

[0099] The configurations of the first engaging portions 62A, 62B and the second engaging portion 63A of the connector cover 60 described in the above embodiment are examples. For example, the first engaging portion may have the same configuration as the second engaging portion 63A in the above embodiment, and the second engaging portion may have the same configuration as the first engaging portions 62A, 62B in the above embodiment. The configurations of the portion of the main body that engages with the first engaging portion and the portion that engages with the second engaging portion can also be changed as appropriate.

[0100] In the above embodiment, the inner surface of the through-hole 65 in the cover wall 61 of the connector cover 60 was in contact with the outer circumference of the cable 55. However, for example, there may be a small gap between the inner surface of the through-hole and the outer circumference of the cable. This makes it easier to pass the cable through the through-hole. Even with such a configuration, the opening for passing the cable can be made smaller compared to, for example, a case where a recess (notch) is formed at one end of the cover wall to allow the cable to pass through. Also, in the above embodiment, the through-hole 65 was circular when viewed from the mounting direction. However, for example, the through-hole may be rectangular or other shapes.

[0101] The elements described in the above embodiments and modifications may be implemented in any combination. [Explanation of Symbols]

[0102] 1 Heating unit 3 belts 3B Inner surface 10 Heaters 11 circuit boards 12 Resistive heating element 18 Power supply terminals 20 holders 26 Retaining part 28. Regulatory aspects 50 connectors 51 Main body 53 Connection terminals 54 Claw part

Claims

1. A heater having a substrate, a resistive heating element supported on the substrate, and a power supply terminal that is electrically connected to the resistive heating element, An endless belt having an inner circumferential surface that contacts the heater and rotating around the heater, A holder that holds the heater, A connector having a connection terminal connected to the power supply terminal, which is attached to the holder by sandwiching a part of the holder and a part of the heater, wherein the connection terminal is connected to the power supply terminal when attached to the holder, The connector has a main body that, when mounted on the holder, sandwiches a part of the holder and a part of the heater, and a claw that protrudes away from the main body. The aforementioned holder is, A support portion that supports the surface of the substrate opposite to the surface that supports the resistive heating element, wherein the substrate is positioned between the support portion and the resistive heating element, A guide portion that guides the inner circumferential surface of the belt, The connector has a retaining portion which, when the claw portion engages with it, restricts the connector from moving upstream in the mounting direction of the connector, A heating unit characterized in that the support portion, the guide portion, and the retaining portion are formed integrally.

2. A heater having a substrate, a resistive heating element supported on the substrate, and a power supply terminal that is electrically connected to the resistive heating element, An endless belt having an inner circumferential surface that contacts the heater and rotating around the heater, A holder that holds the heater, A connector having a connection terminal connected to the power supply terminal, which is attached to the holder by sandwiching a part of the holder and a part of the heater, wherein the connection terminal is connected to the power supply terminal when attached to the holder, The aforementioned connector is The main body portion, when mounted on the holder, sandwiches a part of the holder and a part of the heater, It has a claw portion that protrudes in a direction away from the main body, The aforementioned holder is, The retaining portion, which engages with the aforementioned claw portion, restricts the connector from moving upstream in the mounting direction of the connector, A pair of wall portions facing each other in a direction perpendicular to the mounting direction, the wall portions having a pair of wall portions that sandwich the connector when the connector is mounted on the holder, The heating unit is characterized in that the retaining portion has one end connected to one of the pair of wall portions and the other end connected to the other of the pair of wall portions.

3. A heater having a substrate, a resistive heating element supported on the substrate, and a power supply terminal that is electrically connected to the resistive heating element, An endless belt having an inner circumferential surface that contacts the heater and rotating around the heater, A holder that holds the heater, A connector having a connection terminal connected to the power supply terminal, which is attached to the holder by sandwiching a part of the holder and a part of the heater, wherein the connection terminal is connected to the power supply terminal when attached to the holder, A connector cover to be attached to the connector, the connector cover having a cover wall that covers the upstream side of the connection terminal in the mounting direction of the connector, The aforementioned connector is The main body portion, when mounted on the holder, sandwiches a part of the holder and a part of the heater, It has a claw portion that protrudes in a direction away from the main body, The heating unit is characterized in that the holder has a retaining portion that prevents the connector from moving upstream in the mounting direction when the claw portion engages with it.

4. The heating unit according to claim 2, characterized in that the holder has a connecting wall portion that connects the downstream ends of the pair of wall portions in the mounting direction.

5. The main body portion has a first main body wall and a second main body wall that face each other in an orthogonal direction perpendicular to both the mounting direction and the direction in which the pair of wall portions face each other, and covers the connection terminal. The heating unit is characterized by comprising a connector cover attached to the connector, the connector cover having a cover wall that covers the upstream side of the connection terminal in the mounting direction, as described in claim 4.

6. The cover wall has a through hole through which the cable connected to the connection terminal passes. The heating unit according to claim 5, characterized in that the through hole has a shape that follows the outer circumference of the cable.

7. The connector cover has a first wall extending in the mounting direction from one end of the cover wall in the orthogonal direction, and a second wall extending in the mounting direction from the other end of the cover wall in the orthogonal direction, sandwiching the main body between itself and the first wall. The first wall has a first engaging portion that engages with the main body portion to restrict the connector cover from moving upstream in the mounting direction, The heating unit according to claim 5 or 6, characterized in that the second wall has a second engaging portion that engages with the main body portion to restrict the connector cover from moving upstream in the mounting direction.

8. The connector has an arm portion extending in the mounting direction, one end of which is connected to the main body portion, and the other end of which is an arm portion that is elastically flexible so as to approach the main body portion. The main body portion contacts the side of the holder opposite to the heater, while sandwiching the holder portion and the heater portion between them. The claw portion is formed on the arm portion, The retaining portion is positioned to sandwich the arm portion between the main body portion and the connector when the connector is mounted in the holder. The heating unit according to any one of claims 1 to 7, characterized in that the arm portion elastically bends and contacts the retaining portion when the connector is mounted on the holder.

9. The heating unit according to any one of claims 1 to 8, characterized in that the holder has a restricting surface in which the main body contacts the position upstream of the power supply terminal in the mounting direction, thereby restricting the connector from moving in a direction perpendicular to both the mounting direction and the width direction of the connector.

10. The heating unit according to claim 9, characterized in that the restricting surfaces are arranged on both sides of the retaining portion in the width direction.

Images