Cooling device, image forming device

Abstract

To prevent refrigerant liquid leaking from the parts of multiple tubes connected to equipment from flowing out to the outside. [Solution] The cooling device 6 comprises a tank 61, a main tray 601, a pump 62, a heat exchange unit 6b, a radiator 63, and a plurality of tubes 6c. The pump 62 and the radiator 63 are arranged on the main tray 601. The tank 61 has an upper tray 61b, a tube fixing part 61d, and a liquid discharge part 61e. The upper tray 61b forms the upper surface of the tank 61. The tube fixing part 61d fixes a portion of a pair of specific tubes 6ca to the upper tray 61b so that the pair of specific tubes 6ca penetrate the upper tray 61b. The liquid discharge part 61e forms a liquid discharge passage from the upper tray 61b to the main tray 601.

Description

Technical Field

[0001] The present invention relates to a cooling device and an image forming apparatus including a tank for storing a refrigerant liquid.

Background Art

[0002] Devices constituting an image forming apparatus tend to become hot due to the acceleration of printing processing.

[0003] For example, in an electrophotographic image forming apparatus, toner stored in a developing device may become hot due to frictional heat generated by stirring of the toner. If the temperature of the toner rises, the softened toner may aggregate, which may deteriorate the image quality.

[0004] Therefore, the image forming apparatus may include a cooling device. For example, it is known that an electrophotographic image forming apparatus includes a liquid cooling type cooling device for cooling the developing device (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, in a liquid cooling type cooling device, a pump circulates a refrigerant liquid through a tank, a heat exchange section, and a radiator. The tank, the pump, the heat exchange section, and the radiator are connected by a plurality of tubes.

[0007] The refrigerant liquid vaporizes and slightly leaks from the connection part of the device. Therefore, as the cooling device is used for a long time, the refrigerant liquid in the tank gradually decreases.

[0008] If the level of the refrigerant liquid in the tank falls below the acceptable range, it is necessary to replenish the refrigerant liquid in the tank or replace the tank.

[0009] On the other hand, leakage of the refrigerant liquid may occur in the portions of the multiple tubes that are connected to the equipment. Since the tank is operated for refilling the refrigerant liquid or replacing the tank, leakage of the refrigerant liquid is particularly likely to occur in the portions of the multiple tubes that are connected to the tank.

[0010] It is undesirable for the leaked refrigerant liquid to flow out of the cooling device.

[0011] The object of the present invention is to provide a cooling device and an image forming apparatus that can prevent refrigerant liquid leaking from the parts of multiple tubes connected to the equipment from flowing out to the outside. [Means for solving the problem]

[0012] A cooling device according to one aspect of the present invention comprises a tank, a main tray, a pump, a heat exchange unit, a radiator, and a plurality of tubes. The tank stores a refrigerant liquid. The main tray is positioned adjacent to the tank and is capable of receiving liquid. The pump is positioned on the main tray and circulates the refrigerant liquid. The heat exchange unit performs heat exchange between the refrigerant liquid and the object to be cooled. The radiator is positioned on the main tray and radiates the heat of the refrigerant liquid. The plurality of tubes connect the tank, the pump, the heat exchange unit, and the radiator, forming a circulation path for the refrigerant liquid. The tank has a top tray, a tube fixing section, and a liquid discharge section. The top tray forms the top surface of the tank at a higher position than the main tray and is capable of receiving liquid. The tube fixing portion fixes a portion of a pair of specific tubes, which are among the plurality of tubes and form the inflow passage for the refrigerant liquid into the tank and the outflow passage for the refrigerant liquid from the tank, to the top tray, with the pair penetrating the top tray. The liquid discharge portion is formed on the edge of the top tray and forms a liquid discharge passage from the top tray to the main tray.

[0013] An image forming apparatus according to another aspect of the present invention comprises a printing apparatus for forming an image on a sheet, and a cooling apparatus for cooling a part of the printing apparatus. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a cooling device and an image forming apparatus that can prevent refrigerant liquid leaking from the parts of multiple tubes connected to equipment from flowing out to the outside. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a configuration diagram of an image forming apparatus equipped with a cooling device according to an embodiment. [Figure 2] Figure 2 is a block diagram showing the configuration of a control device in an image forming apparatus equipped with a cooling device according to an embodiment. [Figure 3]FIG. 3 is a perspective view of the main cooling unit in the cooling device according to the embodiment. [Figure 4] FIG. 4 is a plan view of the main cooling unit in the normal state in the cooling device according to the embodiment. [Figure 5] FIG. 5 is a plan view of the main cooling unit in the pulled-out state in the cooling device according to the embodiment. [Figure 6] FIG. 6 is a first perspective view of the tank state detection device when the tank is in the mounting position in the cooling device according to the embodiment. [Figure 7] FIG. 7 is a second perspective view of the tank state detection device when the tank is in the mounting position in the cooling device according to the embodiment. [Figure 8] FIG. 8 is a perspective view of the tank state detection device when the tank is separated from the mounting position in the cooling device according to the embodiment. [Figure 9] FIG. 9 is a perspective view of the liquid leakage detection device in the cooling device according to the embodiment.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are an example of embodying the present invention and do not limit the technical scope of the present invention.

[0017] The cooling device 6 according to the embodiment constitutes a part of the image forming apparatus 10 (see FIG. 1).

[0018] [Configuration of Image Forming Apparatus 10] As shown in FIG. 1, the image forming apparatus 10 includes a sheet conveyance device 3, a printing device 4, and a cooling device 6. Further, the image forming apparatus 10 includes a main body 1 which is a housing that houses the sheet conveyance device 3, the printing device 4, and the cooling device 6.

[0019] The sheet conveying device 3 conveys the sheets 9. The sheet conveying device 3 comprises a sheet feeding mechanism 30 and multiple pairs of conveying rollers 31. The sheet feeding mechanism 30 sends the sheets 9 stored in the sheet storage section 2 to the conveying path 300. The conveying path 300 is the passage through which the sheets 9 are conveyed.

[0020] Multiple sets of conveyor rollers 31 are rotationally driven by a motor (not shown). The multiple sets of conveyor rollers 31 rotate to convey the sheet 9 along the conveyor path 300 and then discharge the sheet 9 to the discharge tray 1x.

[0021] The printing device 4 performs a printing process. The printing process is the process of forming an image on a sheet 9 that is transported by the sheet transport device 3. The sheet 9 is an image-forming medium such as paper or a sheet-shaped resin material.

[0022] In this embodiment, the printing device 4 performs the printing process using an electrophotographic method. The printing device 4 comprises one or more image forming units 4x, a laser scanning unit 5, a transfer device 44, and a fixing device 46.

[0023] In the example shown in Figure 1, the image forming apparatus 10 is a tandem-type color image forming apparatus. Therefore, the printing apparatus 4 is equipped with multiple image forming units 4x corresponding to multiple toner colors.

[0024] Each image forming unit 4x includes a drum-shaped photoreceptor 41, a charging device 42, a developing device 43, and a drum cleaning device 45. In other words, the printing device 4 comprises multiple photoreceptors 41 corresponding to multiple toner colors, multiple developing devices 43, and multiple drum cleaning devices 45.

[0025] In each of the image forming units 4x, the photoreceptor 41 rotates, and the charging device 42 charges the surface of the photoreceptor 41. The laser scanning unit 5 scans each of the charged photoreceptors 41 with multiple laser beams. As a result, an electrostatic latent image is formed on the surface of each photoreceptor 41.

[0026] Each developing device 43 develops the electrostatic latent image into a toner image by supplying toner to the surface of each photoreceptor 41. The toner is a granular developer. The photoreceptor 41 is an example of an image carrier that carries and rotates the toner image.

[0027] In this embodiment, the printing apparatus 4 comprises four image forming units 4x corresponding to the toners of four developing colors: yellow, cyan, magenta, and black. Accordingly, the printing apparatus 4 comprises four photoreceptors 41, four developing units 43, and four drum cleaning units 45.

[0028] Four toner images are formed on the surfaces of the four photoreceptors 41. The transfer device 44 transfers the four toner images from the four photoreceptors 41 to the sheet 9.

[0029] The transfer apparatus 44 includes an intermediate transfer belt 441, four primary transfer devices 442 corresponding to four image forming units 4x, a secondary transfer device 443, and a belt cleaning device 444.

[0030] The four primary transfer devices 442 transfer the toner images from the surfaces of the four photoreceptors 41 to the surface of the intermediate transfer belt 441. As a result, a color toner image, formed by combining the toner images of the four photoreceptors 41, is created on the surface of the intermediate transfer belt 441.

[0031] The secondary transfer device 443 transfers the color toner image formed on the intermediate transfer belt 441 to the sheet 9 at the transfer position in the transport path 300.

[0032] The fixing device 46 heats and pressurizes the color toner image transferred to the sheet 9. In this way, the fixing device 46 fixes the color toner image to the sheet 9.

[0033] Each drum cleaning device 45 removes waste toner remaining on the surface of each photoreceptor 41. The belt cleaning device 444 removes the waste toner remaining on the intermediate transfer belt 441.

[0034] The image forming apparatus 10 further comprises an operating device 801, a display device 802, and a control device 8.

[0035] The operating device 801 is a device that accepts human input. For example, the operating device 801 includes one or both of a touch panel and / or operating buttons.

[0036] The display device 802 is capable of displaying various types of information. For example, the display device 802 is a panel display device such as a liquid crystal display device. The control device 8 controls various electrical devices provided by the image forming apparatus 10.

[0037] As shown in Figure 2, the control device 8 includes a CPU (Central Processing Unit) 80, RAM (Random Access Memory) 81, a secondary storage device 82, a signal interface 83, and a communication device 84, among others.

[0038] The CPU 80 performs various control and data processing by executing computer programs. The RAM 81 is a volatile memory device. The RAM 81 temporarily stores the computer programs executed by the CPU 80 and various data.

[0039] The secondary storage device 82 is a computer-readable, non-volatile storage device. The secondary storage device 82 stores the computer program executed by the CPU 80 and various data. For example, flash memory, a hard disk drive, or both may be used as the secondary storage device 82.

[0040] The signal interface 83 converts detection signals from various sensors into digital detection data. This detection data is transmitted to the CPU 80.

[0041] The communication device 84 performs communication with multiple external devices, including one or more host devices, via a network. The CPU 80 performs communication with each of the external devices via the communication device 84. The host device is an information processing device that requests the image forming apparatus 10 to perform the print processing.

[0042] The CPU 80 includes a plurality of processing modules that are realized by executing the computer program. These plurality of processing modules include a main control unit 8a, a print control unit 8b, and a determination unit 8c, etc. (see Figure 2).

[0043] The main control unit 8a performs processing to receive various requests and controls other modules to execute processing in response to those requests. For example, the main control unit 8a receives a print request through the operating device 801 or the communication device 84. Furthermore, the main control unit 8a causes the print control unit 8b to execute processing in response to the print request.

[0044] The print control unit 8b controls the sheet transport device 3 and the print device 4. The print control unit 8b causes the sheet transport device 3 to transport the sheet 9 while causing the print device 4 to perform the printing process.

[0045] The determination unit 8c determines various states of the image forming apparatus 10 according to the detection status of various sensors in the image forming apparatus 10 and the operating status of various devices.

[0046] The cooling device 6 cools a portion of the printing device 4. The cooling device 6 comprises a main cooling unit 6a, one or more heat exchange units 6b positioned at the location of the object to be cooled, and a plurality of tubes 6c (see Figures 1 and 3).

[0047] The heat exchange unit 6b performs heat exchange between the refrigerant liquid and the object to be cooled. As a result, the heat exchange unit 6b cools the object to be cooled, which is at a higher temperature than the refrigerant liquid.

[0048] The object to be cooled is a part of the printing device 4. In this embodiment, the object to be cooled is the developing device 43 (see Figure 1).

[0049] In this embodiment, the cooling device 6 comprises four heat exchange units 6b, and the objects to be cooled are four developing units 43. That is, the cooling device 6 cools each of the developing units 43. In each of the developing units 43, the cooling device 6 suppresses the temperature rise of the toner caused by frictional heat generated by the stirring of the toner.

[0050] The main cooling unit 6a comprises a support base 60, a main tray 601, a tank support 602, a tank 61, a pump 62, and a radiator 63 (see Figure 3).

[0051] In the liquid-cooled cooling system 6, the pump 62 circulates the refrigerant liquid between the tank 61, the heat exchange unit 6b, and the radiator 63. The tank 61, the pump 62, the heat exchange unit 6b, and the radiator 63 are connected by a plurality of tubes 6c.

[0052] Multiple tubes 6c connect the tank 61, the pump 62, the heat exchange unit 6b, and the radiator 63, forming a circulation path for the refrigerant liquid.

[0053] The refrigerant liquid vaporizes and leaks slightly from the connection points of the equipment. As a result, the amount of refrigerant liquid in the tank 61 gradually decreases as the cooling device 6 is used for a long period of time.

[0054] If the level of the refrigerant liquid in tank 61 falls below the acceptable range, it is necessary to replenish the refrigerant liquid in tank 61 or replace tank 61.

[0055] On the other hand, leakage of the refrigerant liquid may occur in the portions of the multiple tubes 6c that are connected to the equipment. Since the tank 61 is operated for refilling the refrigerant liquid or replacing the tank 61, leakage of the refrigerant liquid is particularly likely to occur in the portions of the multiple tubes 6c that are connected to the tank 61.

[0056] It is undesirable for the leaked refrigerant liquid to flow out of the cooling device 6. Therefore, the cooling device 6 is equipped with a configuration to prevent the refrigerant liquid leaking from the parts of the multiple tubes 6c connected to the equipment from flowing out to the outside.

[0057] In this embodiment, if the level of the refrigerant liquid in the tank 61 falls below an acceptable range, it is necessary to replenish the refrigerant liquid in the tank 61. It is desirable that the cooling device 6 be able to easily replenish the refrigerant liquid in the tank 61.

[0058] The cooling device 6 also includes a configuration for facilitating the replenishment of the refrigerant liquid into the tank 61.

[0059] [Configuration of main cooling unit 6a] As mentioned above, the main cooling unit 6a comprises a support base 60, a main tray 601, a tank support 602, a tank 61, a pump 62, and a radiator 63 (see Figure 3).

[0060] Tank 61 stores the refrigerant liquid. Tank 61 has a cap 61c that closes a replenishment hole 61bx that communicates with the inside (see Figure 3). The cap 61c can open and close the replenishment hole 61bx formed on the upper surface of tank 61. In this embodiment, the cap 61c is a screw cap.

[0061] The main body 1 includes an access opening 1a formed at a position facing the tank 61, and a cover 1b that can open and close the access opening 1a (see Figures 1 and 4). Figure 5 shows the state in which the cover 1b has been removed from the position that closes the access opening 1a on the main body 1.

[0062] The support base 60 supports the main tray 601 and the tank support 602. The main tray 601 is positioned adjacent to the tank 61. The pump 62 and radiator 63 are positioned on the main tray 601. The tank support 602 supports the tank 61.

[0063] In the main tray 601, the outer edge is an annular projection that protrudes upward from the inner portion of the outer edge. This allows the main tray 601 to receive liquid in the inner portion of the outer edge.

[0064] If the refrigerant leaks from the pump 62 or radiator 63, the leaked refrigerant is collected in the main tray 601. The same applies if the refrigerant leaks from the portion of the multiple tubes 6c connected to the pump 62 or radiator 63.

[0065] The radiator 63 radiates the heat from the refrigerant liquid, whose temperature has risen due to heat exchange with the four developing units 43. In the example shown in Figure 3, the radiator 63 is an air-cooling device with a cooling fan.

[0066] The tank support 602 supports the tank 61 and is rotatably supported around a shaft portion 603 that is positioned vertically. The shaft portion 603 is located within the unit area, which is the area occupied by the support base 60 (see Figures 3-5).

[0067] The unit area is an area within the main body 1 and includes the area where the main tray 601 is located. That is, the unit area includes the area where the pump and the radiator are located. In this embodiment, the shaft portion 603 is located in an area along the outer edge of the main tray 601 (see Figures 3-5).

[0068] As the tank support 602 rotates, the tank 61 moves between an operating position where it is contained within the unit area and a replenishment position where the cap 61c protrudes outside the unit area.

[0069] When cover 1b is open, the tank support 602 is pulled outward from the main body 1, causing it to rotate to a position where it protrudes from the inside to the outside of the main body 1 (see Figures 4 and 5). This causes the tank 61 to move from the operating position to the replenishment position.

[0070] Figures 3 and 4 show the main cooling unit 6a when the tank 61 is in the operating position, and Figure 5 shows the main cooling unit 6a when the tank 61 is in the replenishment position.

[0071] When the tank 61 moves from the operating position to the replenishment position, the cap 61c of the tank 61 moves from inside the main body 1 to outside the main body 1 via the access opening 1a (see Figures 4 and 5).

[0072] In other words, when the tank 61 is in the operating position, the cap 61c is inside the main body 1, and when the tank 61 is in the replenishment position, the cap 61c is exposed outside the main body 1. When the tank 61 is in the replenishment position, the cap 61c can be easily removed and the refrigerant liquid can be easily replenished into the tank 61.

[0073] The multiple tubes 6c include a pair of specific tubes 6ca that form an inflow passage for the refrigerant liquid into the tank 61 and an outflow passage for the refrigerant liquid from the tank 61 (see Figures 4 and 5).

[0074] The tank 61 has a tube fixing portion 61d and a tube holding portion 61f (see Figures 3-5).

[0075] The tube fixing portion 61d is the part that fixes a portion of the pair of specific tubes 6ca to the upper surface of the tank 61, with the pair of specific tubes 6ca passing through the upper surface of the tank 61. The tube fixing portion 61d is the part that connects the pair of specific tubes 6ca to the tank 61.

[0076] In this embodiment, the tube fixing portion 61d is composed of a pair of members or a pair of units that individually fix each of the pair of specific tubes 6ca to the upper surface of the tank 61. Alternatively, the tube fixing portion 61d may be composed of a single member or a single unit.

[0077] The tube fixing portion 61d is positioned closer to the shaft portion 603 than the cap 61c. In this embodiment, the tank 61 has an outer shape in which the direction in which the cap 61c and the tube fixing portion 61d are aligned is the longitudinal direction when viewed from above.

[0078] The tube holding portion 61f is provided on the side of the tank 61 (see Figure 3). The tube holding portion 61f holds a portion of a pair of specific tubes 6ca along the extension of the shaft portion 603 (see Figures 3-5).

[0079] The tube holding portion 61f prevents strong tension from being applied to a pair of specific tubes 6ca when the tank 61 rotates together with the tank support 602.

[0080] The tank 61 further includes an upper tray 61b and a liquid discharge section 61e (see Figure 3). The upper tray 61b forms the upper surface of the tank 61 at a higher position than the main tray 601.

[0081] The supply hole 61bx is formed in the top tray 61b. The cap 61c is removably attached to the top tray 61b. The cap 61c closes the supply hole 61bx when attached to the top tray 61b.

[0082] In the top tray 61b, the outer edge is an annular projection that protrudes upward from the inner portion of the outer edge. This allows the top tray 61b to receive liquid in the inner portion of the outer edge.

[0083] The top tray 61b has a smaller liquid storage capacity than the main tray 601. However, if reduced, the main tray 601 can store a larger amount of liquid than the top tray 61b.

[0084] The tube fixing section 61d fixes a portion of the pair of specific tubes 6ca to the top tray 61b in such a state that the pair of specific tubes 6ca penetrate the top tray 61b (see Figure 3).

[0085] The liquid discharge section 61e is formed on the edge of the upper tray 61b and forms a liquid discharge path from the upper tray 61b to the main tray 601.

[0086] If the refrigerant liquid leaks from the tube fixing portion 61d, the leaked refrigerant liquid temporarily accumulates in the upper tray 61b and then flows to the main tray 601 through the liquid discharge portion 61e.

[0087] In the main cooling unit 6a, the size of the tank 61 is larger than the size of the pump 62 and the radiator 63, respectively. If a larger main tray 601 were used and the tank 61 were placed on the main tray 601, the height dimension of the main cooling unit 6a would increase.

[0088] On the other hand, the top tray 61b is shorter than the tube fixing portion 61d and the portion of the pair of specific tubes 6ca that extends from the tube fixing portion 61d. Therefore, the top tray 61b does not affect the height dimension of the tank 61.

[0089] Furthermore, the tank 61 is positioned from a position lower than the main tray 601 to a position higher than the main tray 601 (see Figure 3). This allows for the efficient arrangement of the tank 61, pump 62, and radiator 63, enabling the realization of a main cooling unit 6a with a small height dimension.

[0090] In this embodiment, the tank 61 has a tank body 61a and an upper tray 61b (see Figure 3). The tank body 61a stores the refrigerant liquid and has a body opening 61ax that opens upward (see Figure 3).

[0091] The top tray 61b is removably attached to the tank body 61a. When the top tray 61b is attached to the tank body 61a, it closes the opening 61ax of the main body.

[0092] In this embodiment, the top tray 61b is fixed to the tank body 61a by a snap-fit ​​61ba and a number of screws 61bb (see Figure 3).

[0093] The main cooling unit 6a further includes a tank condition detection device 64 and a leak detection device 65 (see Figures 4-9).

[0094] The tank condition detection device 64 detects the normal state and the abnormal state of the tank 61. The normal state is a state in which the level of the refrigerant liquid in the tank 61 is within an acceptable range when the tank 61 is in the operating position. The abnormal state includes a first abnormal state or a second abnormal state.

[0095] The first abnormal condition is a state in which the level of the refrigerant liquid in the tank 61 falls below the allowable range while the tank 61 is in the operating position. The second abnormal condition is a state in which the tank 61 is not in the operating position.

[0096] In this embodiment, the tank state detection device 64 includes a first float 640, a lower limit limit 61h, a movable member 642, a biasing member 643, and a first object sensor 641 (see Figures 6 and 7).

[0097] The first object sensor 641 detects an object located at a first detection position P1 above the support base 60. As described later, if the movable member 642 or the first floating body 640 is located at the first detection position P1, the first object sensor 641 detects the movable member 642 or the first floating body 640.

[0098] For example, the first object sensor 641 is a transmissive photosensor having a light-emitting unit 641a and a light-receiving unit 641b (see Figures 6 and 8). The first detection position P1 is the position between the light-emitting unit 641a and the light-receiving unit 641b.

[0099] The first float 640 is housed in the tank 61 together with the refrigerant liquid and is an object with a lower density than the refrigerant liquid. The first float 640 floats on the refrigerant liquid in the tank 61. Therefore, the position of the first float 640 changes up and down according to the liquid level of the refrigerant liquid in the tank 61.

[0100] The lower limit limit section 61h is provided on the tank 61 and restricts the vertical range of motion of the first float 640 to a predetermined lower limit position. When the tank 61 is in the operating position, the lower limit position is the first detection position P1 (see Figure 7).

[0101] In this embodiment, the tank 61 further includes a float guide section 61g that limits the horizontal movement range of the first float 640 and guides the first float 640 in the vertical direction (see Figures 6 and 7).

[0102] The movable member 642 is supported so as to be movable between a reference position and a retracted position. Figure 6 shows the movable member 642 in the retracted position, and Figure 8 shows the movable member 642 in the reference position. The movable member 642 has a detected portion 642a that moves to the first detection position P1 when it moves to the reference position, and moves away from the first detection position P1 when it moves to the retracted position (see Figure 8).

[0103] In this embodiment, the movable member 642 is supported so as to be movable in the vertical direction, and the detected portion 642a is the upper end of the movable member 642.

[0104] The biasing member 643 biases the movable member 642 toward the reference position. The biasing member 643 holds the movable member 642 in the reference position when the tank 61 is in the replenishment position (see Figure 8).

[0105] In this embodiment, the biasing member 643 is a spring that biases the movable member 642 upward (see Figures 6 and 8).

[0106] The movable member 642 is held in the retracted position by contacting the tank 61, which is in the operating position (see Figure 6). That is, when the tank 61 is in the operating position, it holds the movable member 642 in the retracted position against the biasing force of the biasing member 643.

[0107] In this embodiment, the lower limit portion 61h of the tank 61 is in contact with the movable member 642. The tank 61 also has a transparent window 61i that transmits light from the light-emitting portion 641a through the first detection position P1 to the light-receiving portion 641b (see Figures 6-8).

[0108] When the tank 61 is located closer to the replenishment position than the operating position, the movable member 642 is held in the reference position by the biasing member 643, and the first object sensor 641 detects the detected part 642a located at the first detection position P1 (see Figure 8).

[0109] On the other hand, when the tank 61 is in the operating position and the liquid level of the refrigerant liquid in the tank 61 falls below the allowable range, the first object sensor 641 detects the first floating body 640 located at the first detection position P1.

[0110] That is, the first object sensor 641 detects either the detected part 642a or the first floating body 640 at the first detection position P1. The state in which the first object sensor 641 detects the detected part 642a is the first abnormal state. The state in which the first object sensor 641 detects the first floating body 640 is the second abnormal state.

[0111] When the abnormal state of the tank 61 is detected by the tank condition detection device 64, the determination unit 8c of the control device 8 notifies the tank abnormality to an output destination such as another device that can communicate via the display device 802 or the communication device 84.

[0112] Furthermore, the print control unit 8b of the control device 8 prohibits the operation of the pump 62 and the execution of the print process when the abnormal state of the tank 61 is detected by the tank state detection device 64.

[0113] The leak detection device 65 detects the liquid accumulated in the main tray 601. That is, the leak detection device 65 detects the refrigerant liquid accumulated in the main tray 601.

[0114] The leak detection device 65 includes a second floating body 650 and a second object sensor 651 (see Figure 9).

[0115] The second object sensor 651 detects an object located at the second detection position P2 within the main tray 601. Specifically, the second object sensor 651 detects the second floating object 650 when it is located at the second detection position P2.

[0116] For example, the second object sensor 651 is a transmissive photosensor having a light-emitting unit 651a and a light-receiving unit 651b (see Figure 9). The second detection position P2 is the position between the light-emitting unit 651a and the light-receiving unit 651b.

[0117] The second float 650 is an object with a lower density than the refrigerant liquid and is placed inside the main tray 601. The second float 650 floats on the refrigerant liquid inside the main tray 601. Therefore, the position of the second float 650 changes up and down according to the liquid level of the refrigerant liquid inside the main tray 601.

[0118] In this embodiment, the main tray 601 has a floating body guide section 601a and an upper limit limit section 601b (see Figure 9). The floating body guide section 601a limits the horizontal movement range of the second floating body 650 and guides the second floating body 650 in the vertical direction (see Figure 9). The upper limit limit section 601b limits the vertical movement range of the second floating body 650 to a range with the second detection position P2 as the upper limit.

[0119] Furthermore, the main tray 601 has a transparent window 601c that transmits light from the light-emitting section 651a through the second detection position P2 to the light-receiving section 651b (see Figure 9).

[0120] When the liquid level of the refrigerant liquid in the main tray 601 rises and the second float 650 reaches the second detection position P2, the second object sensor 651 detects the second float 650 located at the second detection position P2.

[0121] The state in which the second object sensor 651 detects the second floating body 650 is when the refrigerant liquid has accumulated in the main tray 601 beyond the permissible range.

[0122] When the leaked refrigerant liquid is detected by the leak detection device 65, the determination unit 8c of the control device 8 notifies the leak abnormality to an output destination such as another device that can communicate via the display device 802 or the communication device 84.

[0123] Furthermore, the print control unit 8b of the control device 8 prohibits the operation of the pump 62 and the execution of the print process when the leaked refrigerant liquid is detected by the leak detection device 65.

[0124] [First variation] In the cooling device 6, one or both of the first object sensor 641 and the second object sensor 651 may be magnetic sensors. In this case, the detected part 642a, the first floating body 640, or the second floating body 650 detected by the magnetic sensor contains a magnetic material. Alternatively, an ultrasonic sensor may be used as one or both of the first object sensor 641 and the second object sensor 651.

[0125] [Second variation] The object to be cooled by the cooling device 6 may be equipment other than the developing device 43 in the image forming apparatus 10. For example, the cooling device 6 may cool the fixing device 46.

[0126] [Third variation] The cooling device 6 may be applied to an inkjet-type image forming apparatus. For example, the cooling device 6 may cool the inkjet head.

[0127] [Notes on the invention] The following is an overview of the invention extracted from the above-described embodiments. Note that each configuration and processing function described below can be selected and combined as desired.

[0128] <Note 1> A tank for storing refrigerant liquid, A main tray, positioned adjacent to the aforementioned tank and capable of receiving liquid, A pump is placed on the main tray and circulates the refrigerant liquid, A heat exchange unit that performs heat exchange between the refrigerant liquid and the object to be cooled, A radiator is placed on the main tray and radiates the heat of the refrigerant liquid, The system comprises a plurality of tubes that connect the tank, the pump, the heat exchange unit, and the radiator, forming a circulation path for the refrigerant liquid, The aforementioned tank is An upper tray is provided that forms the top surface of the tank at a higher position than the main tray and is capable of receiving liquid. A tube fixing portion is provided for fixing a portion of the pair of specific tubes, which are among the plurality of tubes and form an inflow passage for the refrigerant liquid into the tank and an outflow passage for the refrigerant liquid from the tank, to the upper tray, while the pair of specific tubes penetrate the upper tray. A cooling device having a liquid discharge section formed on the edge of the upper tray, which forms a liquid discharge passage from the upper tray to the main tray.

[0129] <Note 2> The cooling device according to Appendix 1, further comprising a liquid leak detection device for detecting liquid accumulated in the main tray.

[0130] <Note 3> The cooling device according to Appendix 1 or Appendix 2, wherein the tank is positioned from a position lower than the main tray to a position higher than the main tray.

[0131] <Note 4> The cooling device according to any one of the appendices 1 to 3, comprising a tank support that supports the tank and is rotatably supported about a shaft positioned vertically within a unit area including the area in which the pump and the radiator are located.

[0132] <Note 5> The tank is removably mounted on the top tray and has a cap that closes a replenishment hole formed in the top tray. The cooling device according to Appendix 4, wherein the tank support rotates, causing the tank to move between an operating position where it is contained within the unit area and a replenishment position where the cap protrudes outside the unit area.

[0133] <Note 6> The aforementioned tank has a tank body that stores the refrigerant liquid and has an opening at the top, The cooling device according to any one of the above appendices 1 to 5, wherein the above top tray is removably attached to the tank body and closes the opening of the tank body.

[0134] <Note 7> A printing device that forms an image on a sheet, An image forming apparatus comprising a cooling device described in any one of the appendices 1 to 6 for cooling a part of the printing device.

[0135] <Note 8> The aforementioned printing device is A photoreceptor on which an electrostatic latent image is formed on its surface, A developing apparatus that develops the electrostatic latent image into a toner image by supplying toner to the surface of the photoreceptor, The device comprises a transfer apparatus for transferring the toner image from the surface of the photoreceptor to a sheet, The cooling device is an image forming apparatus as described in Appendix 7, which cools the developing apparatus. [Explanation of Symbols]

[0136] 1: Main unit 1a: Access opening 1b: Cover 4: Printing device 6: Cooling device 6a: Main cooling unit 6b: Heat exchange section 6c: Tube 6ca: Specific tube 8: Control device 10: Image forming apparatus 43: Developing equipment 60: Support stand 61: Tank 61b: Top tray 61bx: Supply Hole 61c: Cap 61d: Tube fixing part 61e:Liquid discharge part 61f: Tube holding part 61g: Floating guide section 61h: Lower limit section 61i: Window 62: Pump 63: Radiator 64: Tank condition detection device 65: Leak detection device 601: Main tray 601a: Floating body guide section 601b: Upper limit section 601c: Window 602: Tank support 603: Shaft 640: First floating body 641: First object sensor 642: Movable member 642a: Detected part 643: Biasing member 650: Second floating body 651: Second object sensor P1: First detection position P2: Second detection position

Claims

1. A tank for storing refrigerant liquid, A main tray, positioned adjacent to the aforementioned tank and capable of receiving liquid, A pump is placed on the main tray and circulates the refrigerant liquid, A heat exchange unit that performs heat exchange between the refrigerant liquid and the object to be cooled, A radiator is placed on the main tray and radiates the heat of the refrigerant liquid, The system comprises a plurality of tubes that connect the tank, the pump, the heat exchange unit, and the radiator, forming a circulation path for the refrigerant liquid, The aforementioned tank is An upper tray is provided that forms the top surface of the tank at a higher position than the main tray and is capable of receiving liquid. A tube fixing portion is provided for fixing a portion of the pair of specific tubes, which are among the plurality of tubes and form an inflow passage for the refrigerant liquid into the tank and an outflow passage for the refrigerant liquid from the tank, to the upper tray, while the pair of specific tubes penetrate the upper tray. A cooling device having a liquid discharge section formed on the edge of the upper tray, which forms a liquid discharge passage from the upper tray to the main tray.

2. The cooling device according to claim 1, further comprising a liquid leak detection device for detecting liquid accumulated in the main tray.

3. The cooling device according to claim 1 or claim 2, wherein the tank is arranged from a position lower than the main tray to a position higher than the main tray.

4. The cooling device according to claim 1 or 2, further comprising a tank support that supports the tank and is rotatably supported about a shaft portion positioned vertically within a unit area including the area in which the pump and the radiator are located.

5. The tank is removably mounted on the top tray and has a cap that closes a replenishment hole formed in the top tray. The cooling device according to claim 4, wherein the tank support rotates, causing the tank to move between an operating position where it is contained within the unit area and a replenishment position where the cap protrudes outside the unit area.

6. The aforementioned tank has a tank body that stores the refrigerant liquid and has an opening at the top, The cooling device according to claim 1 or 2, wherein the top tray is removably attached to the tank body and closes the opening of the tank body.

7. A printing device that forms an image on a sheet, An image forming apparatus comprising a cooling device according to claim 1 or 2 for cooling a part of the printing device.

8. The aforementioned printing device is A photoreceptor on which an electrostatic latent image is formed on its surface, A developing apparatus that develops the electrostatic latent image into a toner image by supplying toner to the surface of the photoreceptor, The device comprises a transfer apparatus for transferring the toner image from the surface of the photoreceptor to a sheet, The image forming apparatus according to claim 7, wherein the cooling device cools the developing device.

Images