JP3155386B2 - Thermal fixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing device for transferring an image formed on a photoreceptor by electrophotography to transfer paper and fixing the transferred image.

[0002]

2. Description of the Related Art First, a conventional example will be described with reference to FIG. Reference numeral 1 denotes a cylindrical heat roller having both ends opened, 2 denotes a press roller, and 3 denotes a rod-shaped heater inserted into the heat roller 1. The heat roller 1 is provided on the side plate 4 facing the heat roller 1.
A bearing 5 for rotatably supporting both ends of the outer periphery of the press roller 2 is fixed, and a bearing 6 for rotatably supporting both ends of the press roller 2 is urged upward and is held movably up and down. A gear 7 receiving rotation of a motor is fixed to the outer periphery of one end of the heat roller 1. The cover 8 that covers the periphery of the heat roller 1 and the left and right side plates 4 are connected by screws 9. Further, a connection plate 10, a thermal fuse 11, a thermostat 12, and a thermistor 14 are provided on the inner surface of the cover 8. Further, a terminal 15 resiliently contacting one end of the heater 3 is connected to the connection plate 10 by a screw 16 and fixed to the cover 8. That is, one end of the heater 3 is connected to one pole of a power supply (not shown) through the terminal 15, the connection plate 10, the temperature fuse 11, the thermostat 12, the cable 17, and the connector (not shown). Is connected to the other pole of the power supply via a cable 18 and a connector (not shown).
Further, a metal fitting 19 for holding the other end of the heater 3 is provided on the cover 8.
At the end of the. The power supply is turned on and off by a thermistor 14 that detects the temperature of the heat roller 1.

[0003]

In the conventional structure shown in FIG. 5, a terminal 15 for holding the end of the heater 3 and a metal fitting 19 are provided.
Is fixed to the cover 8, it is necessary to attach and detach the heater 3 with the cover 8 coupled to the side plate 4 when replacing the heater 3. That is, the connector to which the cable 18 is connected is separated, the metal fitting 19 is removed from the cover 8, the heater 3 is pulled out rightward, a new heater 3 is inserted into the center of the heat roller 1 from the right side, and the leading end thereof is inserted. To make contact with the terminal 15. However, since the periphery of the terminal 15 is covered by the cover 8, it is difficult to engage the tip of the terminal 15 with a recess formed at the center of the end of the heater 3.

[0004]

SUMMARY OF THE INVENTION The present invention provides a frame having opposite side plates, and a cylinder having both ends open rotatably supported by bearings provided on the periphery of an opening formed in the side plates. Heat roller, a rotatable press roller pressed against the heat roller, a rod-shaped heater inserted into the center of the heat roller, and a pair of terminals resiliently contacting both ends of the heater. A cover that has a cover that covers the heat roller and is detachably coupled to the frame; a plurality of connection plates connected to a power supply and fixed to an inner surface of the cover; comprising: a connecting portion for connecting the terminal and a terminal holding portion for holding each of said terminals are disposed on opposite sides of the frame
And a connection between the connection plate and the terminal by the connection portion.
The cover is removed from the frame by disconnecting
I can do it.

[0005]

According to the present invention, the pair of terminals connected to the power supply via the connection portion and the connection plate are held by the terminal holding portion of the frame, so that the connection portion is disconnected and the cover is removed from the frame. Thus, the terminal can be stabilized with the pair of terminals open on both sides of the frame, so that the heater can be easily mounted and replaced without the need to connect and disconnect the cable.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. The same parts as those described in FIG. 5 are described using the same reference numerals. FIG. 1 is a cross-sectional view.
Is a frame. Openings 22 for projecting the cylindrical heat roller 1 are formed in side plates 21 formed on both sides of the frame 20, and the outer periphery of the end of the heat roller 1 is rotatably supported on the periphery of the opening 22. Ring bearing 5
Has been fixed. Below the side plate 21, a bearing 6 for rotatably supporting the press roller 2 is urged upward and is held movably up and down. Furthermore, heat roller 1
A gear 7 receiving the rotational force of the motor is fixed to the outer periphery of one end of the gear.

Reference numeral 23 denotes a cover having a cover portion 24 which covers the periphery of the heat roller 1. The cover portion 24 has on its inner surface connection plates 25, 26 located on both sides and metal plates 27, 28 located in the center. The connection plate 25 and the metal plate 27 are connected by the temperature fuse 11, the connection plate 26 and the metal plate 28 are connected by the thermostat 12, and the temperature of the heat roller 1 is applied to the metal plate 28. A thermistor 14 that detects and controls on / off operation of a power supply (not shown) is held. The metal plates 27 and 28 are connected to a power supply for each pole. Further, terminal holding portions 29 and 30 are integrally formed on the side plates 21 on both sides of the frame 20, and the terminal holding portions 29 and 30 are provided with terminals 31 and 32 resiliently contacting the ends of the heater 3. Is held. These terminals 31 and 32 are connected to the connection plates 25 and 26 by screws 33 as connection portions.

Next, the support structure of the right terminal 32 will be described in detail with reference to FIG. The terminal holding portion 30 has a projecting piece shape protruding toward the cover portion 24 of the cover 23,
An elastic piece 34 for holding the protruding terminal holding portion 30 is formed on the terminal 32. The support structure of the left terminal 31 is the same as the support structure of the right terminal 32 except for the symmetrical shape, and therefore the description is omitted.

As shown in FIG. 3, the frame 20 has a paper discharge roller 35 and a paper discharge roller 3 urged downward.
5 is held rotatably with a pressing roller 36 which is in elastic contact with 5. Although not shown, a locking hole and a locking claw that are detachably engaged with each other are formed on the opposing surfaces of the frame 20 and the cover 23.

In such a configuration, when attaching or replacing the heater 3, the screw 33 is removed in the state shown in FIG. 1 to disconnect the connection between the connection plates 25 and 26 and the terminals 31 and 32, and the cover 23 is removed. Remove from frame 20. In this state, as shown in FIG. 2 and FIG.
2 is held by the terminal holding portions 29 and 30 on the frame 20 side in a state where the periphery is opened. Therefore, heater 3
Can be easily exchanged. When the heater 3 is mounted, the terminals 31, 32 are held by the terminal holding portions 29, 30, so that the terminals 31, 32 are kept as they are.
Since the heater 3 can be inserted into the heat roller 1 by elastically bending the heater 32 outward, and the terminals 31 and 32 merely hold the terminal holding portions 29 and 30 with the elastic pieces 34. , Terminals 31 and 32 to terminal holding portions 29 and 3
It can be removed from 0 and inserted into the heat roller 1.
Thereby, the attachment / detachment operation of the heater 3 can be performed extremely easily.

After mounting the heater 3, the cover 23 is engaged with the frame 20. In this case, by determining the dimensional relationship between the frame 20 and the cover 23, the terminals 31,
32 can be pressed by the cover portion 24,
By connecting the terminals 31, 32 to the connection plates 25, 26 at 3, the terminals 31, 32 are more firmly fixed.

[0012]

As described above, according to the present invention, since the terminal holding portions for holding the terminals contacting the both ends of the heater are provided on both sides of the frame to which the cover is detachably connected, the connection plate on the cover side is provided. When the connection between the frame and the terminal on the frame side is cut off and the cover is removed from the frame, it can be stabilized with the pair of terminals open on both sides of the frame, and therefore the work of disconnecting and connecting the cable is required. Therefore, there is an advantage that the heater can be easily attached and replaced without any heater.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a state where a cover is removed from a frame.

FIG. 3 is a perspective view showing a state in which a cover is removed from a frame.

FIG. 4 is a partial exploded perspective view showing a terminal support structure.

FIG. 5 is a sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat roller 2 Press roller 3 Heater 5 Bearing 20 Frame 21 Side plate 22 Opening 23 Cover 24 Covering part 25, 26 Connection plate 29, 30 Terminal holding part 31, 32 Terminal 33 Connection part

Claims (1)

(57) [Claims] 1. A frame having opposite side plates, a cylindrical heat roller having both ends open rotatably supported by bearings provided on the periphery of an opening formed in the side plates, A rotatable press roller pressed against the roller, a rod-shaped heater inserted into the center of the heat roller, a pair of terminals resiliently contacting both ends of the heater, and a cover for covering the heat roller. A cover having a portion and detachably coupled to the frame, a plurality of connection plates connected to a power supply and fixed to an inner surface of the cover, and a connection portion connecting these connection plates and the terminals. ,
A terminal holding portion disposed on both sides of the frame to hold each of the terminals ,
By breaking the connection between the connection plate and the terminal
A heat fixing device wherein the cover can be removed from the frame .