Grease supply unit and conveying heating device

Abstract

To provide a grease supply unit capable of preventing dripping of grease and production of metal waste.SOLUTION: A conveyance chain is provided with: rollers; and link plate parts and attachment-provided link plate parts each having an attachment for conveying a conveyance object, both of which are located respectively on both sides of respective rollers. A grease supply unit for the conveyance chain comprises: one or more idlers which come into contact with the rollers of the conveyance chain; and one or more nozzles which supply grease to outer peripheral surfaces of the idlers, wherein the grease supplied to the idlers is supplied by transferring to the conveyance chain.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a grease supply unit that supplies grease to a chain, and to a conveyance heating device provided with the grease supply unit. [Background Art]

[0002] For example, in a conveyance chain configured as a roller chain, it is important that appropriate lubrication is achieved through oil supply. If lubrication is inadequate, component wear may shorten service life or increase noise. For example, conveyance chains are used in reflow devices to convey electronic components or printed circuit boards. A reflow device comprises a reflow furnace into which an object to be heated, such as a printed circuit board, is supplied by the conveyance chain. The reflow furnace has a configuration in which, for example, a plurality of heating furnaces corresponding to a plurality of zones are sequentially arranged along a conveyance path extending from an inlet to an outlet. The plurality of zones have roles such as a heating zone and a cooling zone depending on their functions.

[0003] In the heating zone, hot air is blown onto the substrate to melt the solder in the solder composition, thereby soldering the electrodes of the printed circuit board to the electronic components. In a reflow device, desired soldering is achieved by controlling the temperature during heating in accordance with a desired temperature profile. In such a reflow device, it is necessary to prevent fine metal scraps from being generated due to friction between the conveyance chain and sprockets, friction between the conveyance chain and guide portions, and the like, and from adhering onto the printed circuit board, so appropriate oil supply is required. Furthermore, it is undesirable for lubricating oil to adhere onto the printed circuit board serving as the object to be heated during oil supply.

[0004] Patent Document 1 describes a lubrication device that can uniformly and reliably lubricate a chain. In Patent Document 1, lubricating oil flows through the lubrication holes of the upper rail and onto the upper surface of the upper key member. The lubricating oil that has flowed onto the upper surface of the upper key member flows from the upper surface to the side surface and is supplied to the end of the bush of the chain. The lubricating oil supplied to the end of the bush enters the gap between the upper key member and the bush, and spreads over the entire upper circumferential surface of the bush. This reduces the frictional resistance between the chain sliding along the lower surface of the upper key member and the upper key member. It also reduces the frictional resistance between the chain sliding along the upper surface of the lower key member and the lower key member. Thus, Patent Document 1 supplies oil to the chain via a transmission member.

[0005] Furthermore, Patent Document 2 describes a configuration for automatically supplying lubricating oil to a chain without stopping the equipment. Specifically, in a reflow oven consisting of a supply unit that supplies oil to the chain and a tank that supplies oil to the supply unit, the tank is provided with a cock to adjust the amount of oil supplied, the supply unit supplies oil by capillary action, and the distance between the supply unit and the chain is made smaller than the length of the oil droplets that hang down from the lower surface of the supply unit due to the balance between gravity and surface tension, and the oil is continuously supplied to the chain at a liquid level while maintaining a distance where the supply unit and the chain do not come into contact. Patent Document 2 employs a configuration that includes a chain cleaning means.

[0006] Patent Document 3 describes an automatic lubrication device for a reflow apparatus equipped with a transport section that transports printed circuit boards using a chain with bushings (pins). This device provides a lubrication device for supplying lubricating oil only to the chain roller section at any position in the transport section. This allows for automatic lubrication of the chain with bushings without the lubricating oil adhering to the printed circuit board, and furthermore, automatic lubrication is possible even while the printed circuit board is being transported, reducing the frequency of lubrication work. In other words, lubricating oil may drip onto the bushings of the chain with bushings, preventing the lubricating oil from adhering to the end face of the printed circuit board and damaging its quality. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 4993015 [Patent Document 2] Patent No. 3801765 [Patent Document 3] Patent No. 3577203 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The apparatus described in Patent Documents 1 to 3 above uses oil (grease). In the case of reflow apparatus, it operates continuously in a high-temperature environment, so low-viscosity oil has problems with durability due to deterioration due to sliding and evaporation at high temperatures. In contrast, grease has a high viscosity and is therefore more durable than oil. Furthermore, it has the advantage of trapping the generated metal debris with grease and preventing grease from adhering to the printed circuit board. On the other hand, it is necessary to prevent the supplied grease from adhering to the pins and then to the printed circuit board, which is the object being heated.

[0009] When applying grease, it is applied to both the upper and lower surfaces (both sides) of the link plate, but this resulted in grease being applied to the rollers sandwiched between the link plates, causing the grease to drip. Furthermore, simply dripping grease did not ensure sufficient adhesion to the chain, requiring a step to spread the grease after dripping. In addition, to regulate the position of the chain as it moves, the chain is held in place by a metal guide, and contact between the chain and the metal guide could potentially generate metal shavings from the upper and lower surfaces.

[0010] Therefore, the object of the present invention is to provide a grease supply unit and a conveying and heating device that can prevent grease from dripping and metal shavings from being generated. [Means for solving the problem]

[0011] The present invention relates to a roller, and link plate portions located on both sides of the roller and Work A grease supply unit for a transport chain, which is provided with an attachment link plate section having an attachment for transporting, Contact with the rollers of the conveyor chain multiple Idler and, Grease is supplied to the outer surface of the idler. multiple Equipped with a nozzle, Multiple idlers consist of a workpiece-side idler that supplies grease to the workpiece-mounting side of the conveyor chain by transfer, and a workpiece-opposite-side idler that supplies grease to the side of the conveyor chain opposite to the workpiece-mounting side by transfer. The multiple nozzles include a workpiece mounting surface side nozzle that supplies grease to the idler on the workpiece mounting surface side, and a workpiece opposite side nozzle that supplies grease to the idler on the opposite side of the workpiece. Workpiece mounting surface side Idler and Workpiece mounting surface side The nozzle supplies grease to the workpiece mounting surface of the conveyor chain by transfer. Workpiece opposite side Idler and Workpiece opposite side This grease supply unit is characterized by supplying grease to the side of the conveying chain opposite to the workpiece mounting surface by transfer using a nozzle. Furthermore, the present invention relates to a heating device having one or more heating furnaces arranged in a grid and configured to blow hot air onto a workpiece using the heating furnaces, and a conveying heating device having a conveying chain for transporting workpieces to the heating device, The conveying chain has rollers, link plate sections located on both sides of the rollers, and attachment link plate sections having attachments for conveying workpieces. A grease supply unit is provided to supply grease to the conveyor chain. The grease supply unit has multiple idlers that contact the rollers of the conveyor chain, It comprises multiple nozzles that supply grease to the outer surfaces of multiple idlers, Multiple idlers consist of a workpiece-side idler that supplies grease to the workpiece-mounting side of the conveyor chain by transfer, and a workpiece-opposite-side idler that supplies grease to the side of the conveyor chain opposite to the workpiece-mounting side by transfer. The multiple nozzles include a workpiece mounting surface side nozzle that supplies grease to the idler on the workpiece mounting surface side, and a workpiece opposite side nozzle that supplies grease to the idler on the opposite side of the workpiece. Workpiece mounting surface side Idler and Workpiece mounting surface sideGrease is supplied by transfer to the workpiece placement surface side of the conveyance chain by a nozzle, Workpiece opposite side and an idler Workpiece opposite side and a nozzle supply grease by transfer to the side of the conveyance chain opposite to the workpiece placement surface; the present invention is characterized thereby, and is a conveyance heating device. [Effect of the Invention]

[0012] According to at least one embodiment, since a transfer method via an idler is employed, sufficient grease can be applied to a specified location, and the steps of applying and spreading grease can be performed simultaneously. Further, since the idler and the chain are always in contact with each other and the chain is driven along the idler, there is an advantage that grease does not adhere to locations other than the specified locations. Furthermore, since it is not necessary to regulate the position of the conveyance chain by means of a metal guide, generation of metal scrap can be suppressed. Note that the effects described herein are not necessarily limited, and any effect described in the present disclosure may be obtained. Further, the content of the present invention is not to be construed as limited by the effects exemplified in the following description. [Brief Description of the Drawings]

[0013] [Figure 1] Fig. 1 is a schematic diagram outlining an example of a reflow device to which the present invention can be applied. [Figure 2] Fig. 2 is a graph showing an example of a temperature profile during reflow. [Figure 3] Fig. 3 is a cross-sectional view for explaining a chain guide portion. [Figure 4] Fig. 4 is a front view used for explaining a conveyance chain. [Figure 5] Fig. 5 is a partially enlarged view of a grease supply unit according to one embodiment of the present invention. [Figure 6] Fig. 6 is an enlarged view of an idler according to one embodiment of the present invention. [Figure 7] Fig. 7 is an enlarged view of an idler according to one embodiment of the present invention. [Figure 8] Figure 8 is a block diagram showing the system configuration of one embodiment of the grease supply control unit. [Figure 9] Figure 9 is a schematic diagram showing the mounting locations of each component of one embodiment of the grease supply control unit on the reflow machine. [Figure 10] Figure 10 is a flowchart showing the processing flow of one embodiment of the grease supply control unit. [Figure 11] Figure 11 is a block diagram showing the system configuration of another embodiment of the grease supply control unit. [Figure 12] Figure 12 is a schematic diagram illustrating the detection of the amount of grease in a tank used as a grease supply container. [Figure 13] Figure 13 is a schematic diagram showing the mounting locations of each component of another embodiment of the grease supply control unit to the reflow machine. [Figure 14] Figure 14 is a flowchart showing the processing flow of another embodiment of the grease supply control unit. [Best Mode for Carrying Out the Invention]

[0014] The present invention will be described below in the following manner, following embodiments. <1. An example of a reflow oven> <2. Grease supply unit> <3. Grease Supply Control Unit> <4. Variation> The embodiment described below is a preferred example of the present invention and is subject to various technically preferred limitations. However, the scope of the present invention is not limited to these embodiments unless otherwise specified in the following description.

[0015] <1. An example of a reflow oven> Figure 1 shows a schematic configuration of a conventional reflow apparatus 101 to which the present invention can be applied. The reflow apparatus 101 comprises a reflow oven 102, a transport chain 103 that passes a workpiece, such as a printed circuit board (hereinafter referred to as a workpiece) W with surface-mount electronic components mounted on both sides, through the reflow oven 102, rotating bodies (idlers, sprockets, etc.) 105a, 105b, 105c, 105d that define the movement path of the transport chain 103, and an outer plate 106. Note that in Figure 1, only one of the two parallel transport chains 103 is shown.

[0016] The reflow oven 102 heats the workpiece W from above and below, and then cools it after heating. The conveyor chain 103 is one of two conveyor chains arranged parallel to the conveying direction. For example, a roller chain is used as the conveyor chain 103. The outer plate 106 is a case that covers the entire unit.

[0017] After the workpiece W is loaded into the reflow oven 102 from the inlet 107, it is transported by the conveyor chain 103 at a predetermined speed in the direction of the arrow (from left to right in Figure 1) and finally removed from the outlet 108. Although not shown, a workpiece loading device for loading the workpiece W is provided before the inlet 107, and a workpiece unloading device for sending the workpiece W to the outside is located after the outlet 108.

[0018] Along the transport path from the inlet 107 to the outlet 108, the reflow oven 102 is sequentially divided into, for example, nine zones Z1 to Z9, and these zones Z1 to Z9 are arranged in line. The seven zones Z1 to Z7 on the inlet 107 side are heating zones, and the two zones Z8 and Z9 on the outlet 108 side are cooling zones. Forced cooling units (not shown) are provided in relation to the cooling zones Z8 and Z9. Note that the number of zones is just an example, and other numbers of zones may be provided. Multiple zones Z1 to Z9 control the temperature of the workpiece W according to the temperature profile during reflow. Each of the heating zones Z1 to Z7 has an upper heating unit and a lower heating unit, each including a blower.

[0019] The aforementioned zones Z1 to Z9 control the temperature of the object to be heated according to the temperature profile during reflow. Figure 2 shows a schematic example of a temperature profile. The horizontal axis represents time, and the vertical axis represents the surface temperature of the object to be heated, such as a printed circuit board on which electronic components are mounted. The first section is the heating section R1 where the temperature rises due to heating, the next section is the preheating section R2 where the temperature remains almost constant, the next section is the reflow (main heating) section R3, and the last section is the cooling section R4.

[0020] The heating section R1 is the period during which the substrate is heated from room temperature to the preheating section R2 (e.g., 150°C to 170°C). The preheating section R2 is a period during which isothermal heating is performed to activate the flux, remove the oxide film on the surface of the electrodes and solder powder, and eliminate uneven heating of the printed circuit board. The reflow section R3 (e.g., peak temperature of 220°C to 240°C) is the period during which the solder melts and the bonding is completed. In the reflow section R3, it is necessary to raise the temperature to a level above the solder melting point. Even after passing through the preheating section R2, uneven temperature rise may exist in the reflow section R3, so heating to a level above the solder melting point is necessary. The final cooling section R4 is a period during which the printed circuit board is rapidly cooled and the solder composition is formed. In the case of lead-free solder, the temperature in the reflow section will be higher (e.g., 240°C to 260°C).

[0021] In Figure 2, curve 1 shows an example of the temperature profile for lead-free solder. An example of the temperature profile for Sn-Pb eutectic solder is shown by curve 2. Since the melting point of lead-free solder is higher than that of eutectic solder, the set temperatures in the preheating section R2 and the reflow section R3 are set higher compared to those for eutectic solder.

[0022] In the reflow apparatus shown in Figure 1, zones Z1 and Z2 are primarily responsible for controlling the temperature of the heating section R1 in Figure 2. Zones Z3, Z4, and Z5 are primarily responsible for controlling the temperature of the preheating section R2. Zones Z6 and Z7 are responsible for controlling the temperature of the reflow section R3. Zones Z8 and Z9 are responsible for controlling the temperature of the cooling section R4.

[0023] <2. Grease supply unit> A grease supply system 11 is provided on the transport chain 103, for example, at a position before the loading entrance 107. The grease supply system 11 may be provided at a position other than the one shown, as long as it is not in the section where the workpiece W is transported. The grease supply system 11 has a grease supply unit 12 and a grease supply control unit 13. The grease supply unit 12 has a grease supply unit 12a that supplies grease to the workpiece mounting surface (upper surface) side 103a of the transport chain 103, and a grease supply unit 12b that supplies grease to the opposite (lower surface) side 103b of the workpiece mounting surface of the transport chain 103. These grease supply units 12a and 12b have the same configuration.

[0024] Grease is supplied from the grease supply control unit 13 to the grease supply units 12a and 12b via piping, and the grease supply units 12a and 12b supply grease to the transport chain 103. Note that the grease supply unit 12 is not limited to supplying grease to both sides of the transport chain 103 as in this example; it may also be configured to supply grease to only one side. The grease supply control unit 13 stores a set amount of grease in a syringe, for example, and dispenses the grease from the syringe using a dispenser. Various types of dispensers can be used, such as pneumatic dispensers or electric motor dispensers. The grease supply system 11 continuously or intermittently supplies grease to one full rotation of the transport chain 103. A similar grease supply system is provided for other transport chains (not shown).

[0025] The reflow apparatus 101 is equipped with an encoder unit that measures the travel distance of the transport chain 103. When the transport chain 103 reaches a predetermined travel distance, an alarm is generated indicating that grease replenishment is necessary. Upon receiving the alarm, grease replenishment is performed. The grease supply control unit 13 stores the amount of grease required for one replenishment in a syringe, for example. An embodiment of the grease supply control unit 13 will be described later.

[0026] The consistency of grease that can be used in the grease supply system 11 described above will now be explained. The consistency of grease is defined as a "JIS number". In this invention, grease with a consistency within the range of JIS numbers 0 to 3, for example, grease with a consistency of JIS number 2, can be used. The state of grease with JIS number 0 is described as "extremely soft" (e.g., tomato ketchup). The state of grease with JIS number 1 is described as "soft" (e.g., mayonnaise). The state of grease with JIS number 2 is described as "normal" (e.g., strained bean paste). The state of grease with JIS number 3 is described as "slightly hard" (e.g., butter).

[0027] If the grease is too soft, it will drip from the conveyor chain and will not be able to trap metal debris. On the other hand, if the grease is too hard, the grease supply control unit 13 will not be able to dispense the grease. Therefore, grease having a consistency within the range described above is used.

[0028] In the reflow apparatus 101 shown in Figure 1, a chain guide section 14 is provided along the transport path from the inlet 107 to the outlet 108. Figure 3 shows a cross-section of the chain guide section 14. The rail 21 has, for example, a U-shaped cross-section perpendicular to the transport path and has an upper rail 25 and a lower rail 26. The upper rail 25 and the lower rail 26 are located above and below the transport chain 103. Chain guides 22 and 23 are attached to the upper rail 25 and the lower rail 26. The chain guides 22 and 23 are, for example, stainless steel rails that extend in the chain transport direction and support the transport chain 103 by sandwiching it from above and below. The transport chain 103 has substrate holding pins 24 for transporting printed circuit boards as workpieces. The substrate holding pins 24 are attachments added for transport and have a shape appropriate to the object being transported. For example, they may be plate-shaped in addition to pins.

[0029] An example of a transport chain 103 in one embodiment will be described. Figure 4 shows the units that make up the transport chain 103. In Figure 4, 31 is a pin, 32a and 32b are inner link plates, 33a and 33b are outer link plates, 34 is a roller, and 35 is a pinned link plate having a substrate holding pin 24. The roller 34 is rotatably mounted on the pin 31. The pin 31 is supported by two parallel opposing inner link plates 32a and 32b, and two parallel opposing outer link plates 33a and 33b. Note that the roller 34 may be a non-rotating member such as a fixed cylindrical body.

[0030] In one embodiment of the present invention, the outer diameter of the roller 34 is smaller than the width of the inner link plates 32a, 32b and the outer link plates 33a, 33b. In the example shown in Figure 4, the widths of the inner link plates 32a, 32b and the outer link plates 33a, 33b are equal, and the width of the pinned link plate 35 is slightly larger than the widths of the inner and outer link plates.

[0031] Grease is applied to the surface of the roller 34. The grease enters the gap between the pin 31 and the roller 34, ensuring proper lubrication. However, if the applied grease adheres to the substrate holding pin 24, there is a risk that the grease will also adhere to the workpiece W, so it is necessary to avoid the grease adhering to the substrate holding pin 24. The inner link plate 32a, outer link plate 33a, and pin-attached link plate 35 will be appropriately referred to as the attachment-attached link plate section 36a, and the inner link plate 32b and outer link plate 33b will be appropriately referred to simply as the link plate section 36b. Attachments other than pins may also be provided.

[0032] Figure 5 shows a magnified view of the grease supply units 12a and 12b. An idler 50a is provided that rolls against the workpiece-mounting side of the transport chain 103 as it moves in the direction of the arrow, and an idler 50b is provided that rolls against the opposite side of the transport chain 103 from the workpiece-mounting side. The idlers 50a and 50b rotate in response to the power of the transport chain 103 and are provided to restrict the transport chain 103 or absorb its elongation. The idlers 50a and 50b are made of metal and have a roller shape.

[0033] Nozzle 51a is supported by mounting plate 52a so that nozzle 51a is positioned above idler 50a. Similarly, nozzle 51b is supported by mounting plate 52b so that nozzle 51b is positioned above idler 50b. Grease is supplied to nozzles 51a and 51b from grease supply control unit 13 through grease supply pipe (not shown), and grease is discharged from the respective tips of nozzles 51a and 51b onto the respective circumferential surfaces of idler 50a and idler 50b, thereby applying grease to the respective circumferential surfaces of idler 50a and idler 50b. The distance between the respective circumferential surfaces of idler 50a and idler 50b and nozzles 51a and nozzle 51b is adjusted, for example, to a range of 0.8 (mm) to 1.2 (mm). If the spacing is narrower than this, there is a risk of interference between the idlers 50a and 50b and the nozzles 51a and 51b, and grease may accumulate. On the other hand, if the spacing is wider than this, there is a risk that grease cannot be applied to the circumferential surface of the idlers 50a and 50b. In one embodiment of the present invention, one grease supply unit is provided on one side of the conveyor chain 103, but two or more grease supply units may be provided. Alternatively, a grease supply unit may be provided on only one side of the conveyor chain 103.

[0034] Figures 6 and 7 show the configuration of the idler 50a in more detail. The configuration of the idler 50b is the same as that of the idler 50a. The idler 50a has a disc 54 that is rotatably mounted on the shaft 53 via a bearing portion 55. As shown in Figure 6, the width of the disc 54 is smaller than the distance between the attachment link plate portion 36a and the link plate portion 36b of the conveyor chain 103, and the circumferential surface of the disc 54 and the circumferential surface of the roller 34 of the conveyor chain 103 are in rolling contact.

[0035] As shown by the arrows in Figure 7, the disc 54 of the idler 50a rotates counterclockwise as the transport chain 103 moves. Grease is discharged from a nozzle (not shown) above the disc 54, and the grease is applied to the circumferential surface of the disc 54. As the disc 54 rotates, the grease is applied to the circumferential surface of the roller 34 of the transport chain 103.

[0036] Thus, in one embodiment of the present invention, grease is transferred to the conveyor chain 103 via the idler disc 54, so the processes of applying grease and spreading grease can be performed simultaneously. Furthermore, since the disc 54 and the conveyor chain 103 are always in contact and the conveyor chain 103 runs along the disc 54, grease does not adhere to areas other than the designated location. In addition, since the trajectory of the conveyor chain 103 is restricted by the disc 54 of the grease supply unit, the generation of metal shavings by the grease supply unit can be suppressed.

[0037] <3. Grease Supply Control Unit> Next, we will describe the grease supply control unit for supplying grease to the grease supply unit mentioned above. Conventionally, after a predetermined period (for example, about 3 months), an operator would apply grease to the conveyor chain. However, if the operating conditions change within the predetermined period, the distance traveled by the conveyor chain is not constant, and the wear state of the chain also differs. In other words, considering the differences in wear state, the appropriate timing for grease application differs for each device. Therefore, setting a predetermined period uniformly made it difficult to apply grease at the appropriate timing.

[0038] The grease supply control unit described below determines the timing of grease application based on the actual cumulative mileage of the conveyor chain, rather than on a time period. This method allows for grease application at the appropriate timing for each device.

[0039] Figure 8 is a block diagram showing the system configuration of one embodiment of a grease supply control unit. In Figure 8, thick lines represent air or grease paths, and solid lines represent electrical signal paths. The grease supply control unit is equipped with a control means (sequencer), such as a PLC (Programmable Logic Controller) 61. A PC (Personal Computer) and a display 62 are connected to the PLC 61.

[0040] The output of the encoder unit 63 is supplied to the PLC 61. The encoder unit 63 is an example of a means for detecting the travel distance of the conveyor chain 103. The encoder unit 63 consists of, for example, a disc attached to the drive shaft of the conveyor chain 103 and an optical sensor provided close to the disc, and generates a travel distance signal (e.g., number of pulses) that is proportional to the rotation speed of the drive shaft, i.e., the travel distance of the conveyor chain 103. When the conveyor chain reaches a predetermined cumulative travel distance, the PLC 61 generates a coating preparation signal. The PLC 61 and the encoder unit 63 are installed inside the reflow apparatus. The PC and display 62 are installed on top of the reflow apparatus, and the operator operates the PC while looking at the display screen.

[0041] The PLC61 controls the reflow machine according to a program set by the PC and display 62. A grease application controller 71 controlled by the PLC61 is provided. In addition to the grease application controller 71, the PLC61 controls the entire system of the reflow machine. For example, it controls the travel speed of the transport chain 103, the temperature of each zone, and the axial flow fans of each zone. One of the control processes of the PLC61 is the control process for grease supply.

[0042] The grease application controller 71, which is externally attached to the reflow machine, is equipped with a syringe 72 and a dispenser (air dispenser) 73. The syringe 72 is filled with the amount of grease necessary to apply grease to both sides of, for example, one conveyor chain 103. The grease application controller 71 is supplied with power, such as commercial power 74 and air, and the grease in the syringe 72 is dispensed to nozzles 51a and 51b by the air pressure of the dispenser 73. The amount of grease required for one application is determined according to the total length of the conveyor chain 103, or it is set to the amount required by the longest of the multiple conveyor chain lengths 103.

[0043] The dispenser 73 has a built-in timer, for example, which allows the dispensing time to be controlled. The amount of grease dispensed from the syringe 72 to the nozzles 51a and 51b is expressed as (air pressure × dispensing time). Note that even with the same air pressure and dispensing time, the amount dispensed will vary depending on the consistency of the grease. The dispenser 73 is also provided with a start switch, and when the start switch is pressed, air is supplied to the syringe 72, and the supply of air is stopped by the timer after a set time has elapsed. Alternatively, the ON / OFF of the dispenser 73 may be controlled by the timer function of the PLC 61.

[0044] Figure 9 is a schematic diagram showing the mounting locations of each component of the grease supply control unit on the reflow apparatus 101. The same reference numerals are used for parts corresponding to the reflow apparatus in Figure 1. However, the transport direction is reversed compared to Figure 1, with the workpiece being transported from right to left when viewed from Figure 9. An encoder unit 63, consisting of a disc and a photodetector, is provided on the drive sprocket 109 of the transport chain 103.

[0045] A distance traveled signal from the encoder unit 63 is supplied to the PLC 61 installed in the control box 110, and the distance traveled is accumulated to calculate the cumulative distance traveled. A PC and display 62 are installed on the side of the reflow machine's entrance. Furthermore, a dispenser 73 is attached on the side of the entrance. Power is supplied to the dispenser 73 via the control box 110. Air is supplied to the dispenser 73, and the air from the dispenser 73 is supplied to the syringe 72. The grease dispensed from the syringe 72 is supplied to the respective nozzles of the grease supply units 12a and 12b described above.

[0046] The processing of one embodiment of the grease supply control unit described above will now be explained. As an example, it is set to apply grease every X(m) of the cumulative travel distance of the transport chain 103. This cumulative travel distance X(m) is calculated by the following formula. X(m) = conveying speed of conveyor chain × operating time × operating days The conveyor chain speed, operating time, and operating days are values ​​that correspond to the user operating the reflow machine, and these values ​​are pre-set by the PC and display 62. The cumulative travel distance X(m) corresponds to the number of pulses measured by the encoder unit 63, so the cumulative travel distance X(m) is set as the number of pulses. As an example of specific values, X = 14400m and the number of pulses = approximately 6 million.

[0047] The processes performed by the control of the PLC61 will be explained by referring to the flowchart in Figure 9. Step S1: The mileage signal from the encoder unit 63 is accumulated, and when it is determined that the cumulative mileage has reached a value corresponding to the set X(m), a grease application alarm is generated as a signal to prepare for application. An alarm sounds, and a message such as "Please apply grease" is displayed on the screens of the PC and the display 62.

[0048] Step S2: The grease application alarm is deactivated. This can be done, for example, by the operator pressing the reset button. Once deactivated, the mileage counting operation for the next application cycle resumes.

[0049] Step S3: Preparation for grease application is made. That is, the syringe 72 filled with grease is placed in the designated location and connected to and configured with the dispenser 73 of the grease application controller 71. The settings for the dispenser 73 include air pressure, air supply time, etc.

[0050] Step S4: The switch on the dispenser 73 of the grease application controller 71 is manually turned ON, and the built-in timer starts. Step S5: Grease application begins. Step S6: When the time set by the timer built into the dispenser 73 is detected to have elapsed, the grease application is completed. Completion is indicated, for example, by a buzzer. A completion message may also be displayed on the screens of the PC and the display 62.

[0051] Step S7: The cumulative mileage is determined based on the mileage signal output from the encoder unit 63. If it is determined that the cumulative mileage has reached the set X(m), the process moves to step S1. From step S1 onward, the processes described above are carried out.

[0052] According to one embodiment of the grease supply control unit described above, the timing of grease application is determined by the actual cumulative travel distance of the transport chain 103, so that grease can be applied at an appropriate time.

[0053] Other embodiments of the grease supply control unit will be described. These other embodiments are similar to the first embodiment in that they determine the timing of grease application based on the actual cumulative mileage of the transport chain 103. Furthermore, these other embodiments automate the control processes for grease replenishment and grease application.

[0054] Figure 11 is a block diagram showing the system configuration of another embodiment of the grease supply control unit. Similar to the first embodiment, the grease supply control unit is provided with a control means (sequencer), such as a PLC61, to which a PC and a display 62 are connected, and a mileage signal is supplied to the PLC61 from an encoder unit 63. In Figure 11, thick lines represent air or grease paths, and solid lines represent electrical signal paths.

[0055] Furthermore, a color detection sensor (e.g., a color fiber sensor) 64 is provided to determine the color of the grease being applied, and the detection output of the color detection sensor 64 is supplied to the PLC 61. The color detection sensor 64 is provided to determine the degree of deterioration of the grease on the transport chain by its color. When the grease deteriorates, the color detection sensor 64 detects that its color turns brown and outputs the detection result to the PLC 61.

[0056] In other embodiments, a grease application controller is provided inside the reflow apparatus. The grease application controller includes a tank 82 as a grease supply container, a dispenser 83, and a laser sensor 85 as a grease quantity detection means for detecting the amount of grease in the tank 82. Air and commercial power 84 are supplied to the dispenser 83. Grease is stored in the tank 82. The grease in the tank 82 is discharged to nozzles 51a and 51b by the air pressure from the dispenser 83. Power is supplied to the dispenser 83, and the dispenser 83 is controlled by a PLC 61. The grease discharge time of the dispenser 83 can be controlled by a timer on the PLC 61. The amount of grease discharged from the tank 82 to nozzles 51a and 51b is expressed as (air pressure × discharge time). Note that the discharge amount changes depending on the consistency of the grease.

[0057] As shown in Figures 12A and 12B, the laser sensor 85 detects the liquid level of the grease in the tank 82. The laser sensor 85 measures the distance to the liquid level of the grease in the tank 82. An upper limit (Figure 12A) and a lower limit (Figure 12B) for the liquid level are set. When the liquid level reaches the lower limit, an announcement (display and / or sound of a message) prompting grease replenishment is made by the PC and the display 62, and grease is replenished by the filler. Grease replenishment may be done automatically from the grease storage unit, or the entire tank filled with grease may be replaced.

[0058] Furthermore, the amount of grease to be dispensed is calculated from the change in the liquid level in tank 82. The amount of grease to be dispensed is calculated from the measurement value of the laser sensor 85 during grease application, and the air pressure of dispenser 83 is controlled so that this amount of grease to be dispensed is set to a specific value. For example, if the amount of grease to be dispensed is too low, PLC 61 controls dispenser 83 to increase its pressure.

[0059] Figure 13 is a schematic diagram showing the mounting locations of each component of the grease supply control unit on the reflow apparatus 101. The same reference numerals are used for parts corresponding to the reflow apparatus in Figure 1. However, the transport direction is reversed compared to Figure 1, with the workpiece being transported from right to left when viewed from Figure 13. An encoder unit 63, consisting of a disc and a photodetector, is provided on the drive sprocket 109 of the transport chain 103.

[0060] A distance signal from the encoder unit 63 is supplied to the PLC 61 installed in the control box 110. A PC and display 62 are installed on the side of the reflow machine's entrance. Furthermore, a dispenser 83 is attached on the side of the entrance. Commercial power is supplied to the dispenser 83 from the control box 110. Air is supplied to the dispenser 83, and the air from the dispenser 83 is supplied to the tank 82. The grease discharged from the tank 82 by the air pressure is supplied to the respective nozzles of the grease supply units 12a and 12b.

[0061] The processing of another embodiment of the grease supply control unit described above will now be explained. Similar to the first embodiment, it is set to apply grease each time the driving distance reaches a set value X (m). The processing performed by the control of the PLC61 will be explained with reference to the flowchart in Figure 14.

[0062] Step S11: The length of the transport chain 103 is set by the PC and the display 62. As a result, the grease application time is set. Step S12: A notification is given to apply grease. Prior to application, an announcement (display and / or sound of a message) is made by the PC and display 62.

[0063] Step S13: A grease application alarm is generated as a signal to prepare for application. An alarm sounds, and a message such as "Please apply grease" is displayed on the screens of the PC and display 62.

[0064] Step S14: The dispenser 83 is turned ON by a control signal from the PLC 61, and the grease application timer is turned ON. This operation is performed, for example, when a control signal is being issued, such as after the device has finished operating or while the device is cooling down. Step S15: Grease application starts automatically. Step S16: While grease is being applied, the pressure of the dispenser 83 is readjusted to an appropriate value based on the measurement results of the laser sensor 85.

[0065] Step S17: The grease application timer in PLC61 reaches 0, and grease application stops. Step S18: Completion of grease application. Completion is indicated by a message and / or buzzer. The cumulative mileage (number of pulses) is reset, and the counting operation of the mileage signal from encoder unit 63 resumes.

[0066] Step S19: Based on the detection results by the laser sensor 85, it is determined whether the grease in the tank 82 is at the lower limit. If the grease in the tank 82 is at the lower limit, a notification (sound or screen display) is given to replenish the grease. Replenishing the grease may be done manually or automatically. Step S20: The cumulative mileage is determined based on the mileage signal output from the encoder unit 63, and the grease color is determined by the color detection sensor 64. When it is determined that the cumulative mileage has reached the set distance, an alarm is generated as a signal to prepare for application, and the process moves to step S12 (grease application notification). From step S12 onward, the processes described above are carried out. Also, if it is detected that the grease color has changed to a color that requires replacement, the process moves to step S12 (grease application notification) even before the cumulative mileage has reached the set value.

[0067] According to other embodiments of the grease supply control unit described above, the timing of grease application is determined by the actual cumulative mileage of the transport chain 103 or by the change in the color of the grease, so that grease can be applied at the appropriate time. In addition, there is the advantage that the grease application process can be automated.

[0068] <4. Variation> Although embodiments of the present invention have been specifically described above, the invention is not limited to the embodiments described above, and various modifications are possible based on the technical concept of the present invention. For example, the present invention can be applied not only to printed circuit boards, but also to flexible circuit boards, circuit boards made by bonding rigid circuit boards and flexible circuit boards, and rigid-flex circuit boards that combine these. Furthermore, the present invention can be applied to reflow equipment with a single-stage (single-zone) heating furnace. Moreover, it can be applied not only to reflow equipment, but also to heating equipment for curing resins, etc. Furthermore, the present invention can be applied to lubrication equipment for conveying chains of equipment other than conveying heating equipment. In addition, the configurations, methods, processes, shapes, materials, and numerical values ​​listed in the above embodiments are merely examples, and different configurations, methods, processes, shapes, materials, and numerical values ​​may be used as needed. Furthermore, the configurations, methods, processes, shapes, materials, and numerical values ​​of the above embodiments can be combined with each other as long as they do not depart from the spirit of the present invention. [Explanation of symbols]

[0069] 101... Reflow machine, 103... Conveyor chain, W... Workpiece, 11...Grease supply system, 12a, 12b...Grease supply unit, 13...Grease supply control unit, 14...Chain guide unit, 24... Circuit board retaining pins, 36a... Link plate section with attachment, 36b...Link plate section, 50a, 50b...Idler, 51a, 51b... Nozzles, 54... Discs, 61... PLC, 63... Encoder unit, 72... Syringe, 73, 83... dispensers, 82... tanks

Claims

1. A grease supply unit for a transport chain provided with rollers, link plate sections located on both sides of the rollers, and an attachment-equipped link plate section having an attachment for transporting a workpiece, A plurality of idlers that contact the rollers of the conveying chain, The idler comprises a plurality of nozzles that supply grease to the outer circumferential surface of the idler, The plurality of idlers include workpiece-side idlers that supply grease to the workpiece-mounting surface side of the transport chain by transfer, and workpiece-opposite-side idlers that supply grease to the side of the transport chain opposite to the workpiece-mounting surface by transfer. The plurality of nozzles include a workpiece mounting surface side nozzle that supplies grease to the workpiece mounting surface side idler, and a workpiece opposite side nozzle that supplies grease to the workpiece opposite side idler. A grease supply unit characterized in that grease is supplied to the workpiece mounting side of the transport chain by transfer using the workpiece mounting side idler and the workpiece mounting side nozzle, and grease is supplied to the side of the transport chain opposite to the workpiece mounting side by transfer using the workpiece opposite side idler and the workpiece opposite side nozzle.

2. The grease supply unit according to claim 1, wherein the grease is a grease with a consistency that falls within the range of JIS numbers 0 to 3.

3. A heating device comprising one or more heating furnaces arranged in a grid, configured to blow hot air onto a workpiece using the heating furnaces, and a conveying heating device having a conveying chain for transporting the workpiece to the heating device, The transport chain comprises rollers, link plate sections located on both sides of the rollers, and attachment-equipped link plate sections having attachments for transporting the workpiece. A grease supply unit is provided to supply grease to the conveying chain. The grease supply unit includes a plurality of idlers that contact the rollers of the transport chain, The system comprises a plurality of nozzles that supply grease to the outer circumferential surfaces of the plurality of idlers, The plurality of idlers include workpiece-side idlers that supply grease to the workpiece-mounting surface side of the transport chain by transfer, and workpiece-opposite-side idlers that supply grease to the side of the transport chain opposite to the workpiece-mounting surface by transfer. The plurality of nozzles include a workpiece mounting surface side nozzle that supplies grease to the workpiece mounting surface side idler, and a workpiece opposite side nozzle that supplies grease to the workpiece opposite side idler. A conveying and heating device characterized in that grease is supplied to the workpiece mounting side of the conveying chain by transfer using the workpiece mounting side idler and the workpiece mounting side nozzle, and grease is supplied to the side of the conveying chain opposite to the workpiece mounting side by transfer using the workpiece opposite side idler and the workpiece opposite side nozzle.

4. A detection means for detecting the travel distance of the conveyor chain, The system comprises a control means to which a mileage signal from the detection means is supplied, The conveying heating device according to claim 3, characterized in that the control means generates a grease supply unit preparation signal when the conveying chain reaches a predetermined cumulative travel distance.

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