Jet-flow height measurement device and jet-flow height measurement method

Abstract

A jet-flow height measurement device according to the present disclosure is configured so as to be able to measure the height of jet flow generated in a jet-flow-type solder tank. The jet-flow height measurement device comprises: a light projection unit that emits light; a light reception unit that receives light; and an information generation unit. The light projection unit emits light to a lateral side of a jet flow of molten solder jetted out by a jetting pump of the solder tank. The light reception unit is disposed at a position facing the light projection unit across the jet flow. The information generation unit generates information indicating the height of the jet flow on the basis of an output from the light reception unit.

Description

Jet height measuring device and jet height measuring method

[0001] The present disclosure relates to a jet height measuring device and a jet height measuring method that can measure the height of a jet of a jet-type solder bath.

[0002] Jet-type solder baths used for soldering have been known for some time (see, for example, Patent Document 1). In soldering operations using jet-type solder baths, molten solder stored in a solder bath is steadily jetted upward by a jet nozzle. A substrate or other object to be soldered is brought into contact with the jetted molten solder while being moved over the jetted molten solder on a conveyor or the like, and soldered. Therefore, in soldering operations using jet-type solder baths, controlling the height of the molten solder jet (jet height) can be an important factor in controlling the quality of soldering. However, it is difficult to measure the height of a specular object such as solder using a light-reflecting displacement sensor, which is commonly used for height measurement.

[0003] Japanese Patent Application Laid-Open No. 2004-186205

[0004] There is a need for a technology to control the quality of soldering work using a jet-type solder bath.

[0005] The jet height measuring device according to the present disclosure comprises a light-projecting unit that irradiates light from the side onto the jet of molten solder sprayed by the spray pump of the solder bath, a light-receiving unit that faces the light-projecting unit across the jet, and an information generating unit that generates information representing the height of the jet based on the output of the light-receiving unit.

[0006] FIG. 1 is a perspective view showing a jet height measuring device according to this embodiment together with a solder bath. FIG. 2 is a functional block diagram of the jet height measuring device according to this embodiment. FIG. 3 is a perspective view showing the jet height measuring device according to this embodiment. FIG. 4 is a front view of the jet height measuring device of FIG. 3. FIG. 5 is a bottom view of the jet height measuring device of FIG. 3. FIG. 6 is a side view of the jet height measuring device of FIG. 3. FIG. 7 is a front view showing a state in which the jet height of a primary jet of a solder bath is being measured using the jet height measuring device according to this embodiment. FIG. 8 is a front view showing a state in which the jet height of a secondary jet of a solder bath is being measured using the jet height measuring device according to this embodiment. FIG. 9 is a front view showing a state in which the liquid level of a solder bath is being measured using the jet height measuring device according to this embodiment.

[0007] Hereinafter, a jet height measuring device according to this embodiment will be described with reference to the drawings. In the following description, components having substantially the same functions and configurations are designated by the same reference numerals, and redundant description will be given only when necessary.

[0008] In this embodiment, the terms are defined as follows: Solder bath: A jet-type solder bath. The solder bath has a reservoir tank in which molten solder is stored. The reservoir tank has a primary jet nozzle and a secondary jet nozzle arranged side by side at a predetermined distance. These are driven simultaneously, generating two types of jets, the primary jet and the secondary jet, simultaneously into the reservoir tank. Of course, the solder bath may be a jet-type solder bath capable of generating only one jet. Solder bath primary jet: A wave-shaped jet generated by forcefully ejecting molten solder from the primary jet nozzle. For example, by passing a board through the primary jet, the molten solder can be distributed to every corner of the soldered portion of the board. Solder bath secondary jet: A flat jet generated by gently ejecting molten solder from the secondary jet nozzle. For example, by passing a board through the secondary jet, the soldered portion of the board can be neatly soldered. Solder bath liquid level: The surface of the molten solder stored in the storage tank when the primary and secondary jets are not being generated. Jet (liquid surface) height: One purpose of measuring the jet (liquid surface) height in this embodiment is to confirm whether the jet height and liquid surface height are the same as those of the previous use so that the solder bath can be used under the same conditions as the previous use. Another purpose is to confirm whether the jet height measured by the jet height measuring device is a height appropriate for the soldering operation verified by the jet height measuring device. Therefore, it is sufficient to know the deviation of the jet (liquid surface) height from the previous use or from a predetermined jet (liquid surface) height. The jet (liquid surface) height measured in this embodiment does not need to be an absolute height, but is typically a relative height.

[0009] In this embodiment, the axes are defined as follows: X-axis: An axis parallel to the width direction (left-right direction) of the solder bath. The X-axis direction is parallel to the direction in which the primary and secondary jets generated in the solder bath are arranged (the direction crossing the primary and secondary jets). When soldering a board using a solder bath, the board is transported along the X-axis. Therefore, the X-axis direction is also called the transport direction. Z-axis: An axis parallel to the height direction (up-down direction) of the solder bath. The Z-axis direction is parallel to the direction of the primary and secondary jets. Y-axis: An axis parallel to the length direction (front-back direction) of the solder bath.

[0010] FIG. 1 is a perspective view showing a jet height measurement device 1 according to this embodiment together with a solder tank 9. As shown in FIG. 1, the solder tank 9 has a reservoir 91 in which molten solder is stored. A primary jet 101 and a secondary jet 102 are generated in the reservoir 91. The primary jet 101 and the secondary jet 102 are generated side by side in the left-right direction, facing upward from the opening of the reservoir 91. Bushings 93 are attached to the outer surfaces of the left and right side walls of the reservoir 91 as receiving portions for receiving pins 29 and 39 of a support frame 2, which will be described later. The jet height measurement device 1 according to this embodiment is disposed so as to straddle the opening of the reservoir 91 on both sides, and is fixed to the solder tank 9.

[0011] The functions of the jet height measurement device 1 will be described below with reference to FIG. 2 . FIG. 2 is a functional block diagram of the jet height measurement device 1 according to this embodiment. Typically, the functions of the jet height measurement device 1 are realized by an image sensor-based transmission-type photoelectric sensor (hereinafter simply referred to as a sensor). Specifically, as shown in FIG. 2 , the jet height measurement device 1 includes a light-projecting unit 5, a light-receiving unit 6, and a control device (controller) 3 that controls the light-projecting unit 5 and the light-receiving unit 6. For example, the light-projecting unit 5 includes a light-projecting element that generates laser light and a lens that converts the laser light generated by the light-projecting element into a band-shaped (line-shaped) light that extends in a one-dimensional direction. The light-projecting unit 5 generates the band-shaped laser light under the control of the control device 3. The light-receiving unit 6 includes a plurality of light-receiving elements arranged in a one-dimensional direction. Each of the plurality of light-receiving elements generates an electrical signal corresponding to the amount of light received. The electrical signals generated by each of the plurality of light receiving elements are input to the control device 3 together with information identifying each light receiving element, and are used in the process of determining whether each light receiving element is ON or OFF.

[0012] The control device 3 is a computer device in which a RAM 12, a ROM 13, a storage device 14, an input controller 15, and a display controller 16 are connected to a processor 11 via a data / control bus 10. An optional input device 18 such as a keyboard, a mouse, or an operation button is connected to the input controller 15. A user can input instructions to start measuring the jet height, to start measuring the liquid level height, to set a threshold, and to set the display by operating the input device 18. An optional display device 19 such as an organic EL display or a segment indicator is connected to the display controller 16. The display device 19 displays information indicating the jet height generated by an information generating unit 114 (described later), information indicating the liquid level height, and the like.

[0013] The ROM 13 or the storage device 14 stores a control program as well as various data required to execute the control program. The various data required to execute the control program include, for example, information regarding thresholds used in processing by a determination unit 112 (described later), arrangement information for each light-receiving element used in processing by an information generation unit 114 (described later), and height information assigned to each light-receiving element. The RAM 12 functions as a main memory, work area, etc. for the processor 11. The control program loaded into the RAM 12 from the ROM 13 or the storage device 14 is executed by the processor 11, whereby the light-projecting unit 5 and the light-receiving unit 6 are controlled in accordance with the control program, and measurement of the jet height or liquid level height is realized. In the process of measuring the jet height or liquid level height, the processor 11 functions as the determination unit 112 and the information generation unit 114.

[0014] The determination unit 112 determines whether each light receiving element is ON or OFF based on the output of each light receiving element. For example, when the amount of light received by a light receiving element is less than a threshold, the determination unit 112 determines that the light receiving element is "OFF," and when the amount of light received is equal to or greater than the threshold, the determination unit 112 determines that the light receiving element is "ON."

[0015] The information generating unit 114 generates information representing the height of the jet or the height of the liquid surface based on the output of the light receiving unit 6. For example, the information representing the height of the jet (height of the liquid surface) may include information regarding the ON / OFF states of each of the plurality of light receiving elements, information identifying the light receiving element that is the ON / OFF boundary among the plurality of light receiving elements arranged in a row, etc. Since the plurality of light receiving elements are arranged along the height direction of the jet (Z-axis direction), the light receiving element that is the ON / OFF boundary represents the height of the jet. Alternatively, each light receiving element may be assigned a relative height with respect to a predetermined reference plane in advance, and the relative height assigned to the light receiving element that is the ON / OFF boundary may be used as information representing the height of the jet or the height of the liquid surface.

[0016] Note that due to fluctuations of the jet or the liquid surface, the information representing the height of the jet or the height of the liquid surface generated by the information generating unit 114 may fluctuate for each sampling. Therefore, the information representing the height of the jet or the height of the liquid surface generated by the information generating unit 114 may be information representing the average height of a predetermined number of samplings, or information representing the maximum value or minimum value of the predetermined number of samplings.

[0017] The configuration of the jet height measurement device 1 according to this embodiment will be described below with reference to Figures 3 to 6. Figures 3, 4, 5, and 6 respectively show a perspective view, a front view, a bottom view, and a side view of the jet height measurement device 1 according to this embodiment. The jet height measurement device 1 according to this embodiment has a light-projecting unit 5, a light-receiving unit 6, a shielding member 8, and a support frame 2. The support frame 2 supports the light-projecting unit 5, the light-receiving unit 6, and the shielding member 8 together.

[0018] The light-projecting unit 5 and the light-receiving unit 6 have rectangular parallelepiped housings 51 and 61, respectively. The support frame 2 is configured so that the light-projecting unit 5 and the light-receiving unit 6 can be disposed on both the left and right sides of the primary jet 101 and the secondary jet 102 (i.e., on both the left and right edges of the storage tank 91). For example, the support frame 2 is configured so that its general shape is generally U-shaped.

[0019] Specifically, the support frame 2 has a pair of block-shaped first and second pedestals 21 and 31. A handle 22 for carrying is attached to the surface of the first pedestal 21. A pair of slender, columnar legs 23 and 24 are attached to the back surface of the first pedestal 21 at a predetermined distance in the Y-axis direction. A housing 51 of the light-projecting unit 5 is attached to the back surface of the first pedestal 21 so as to be suspended between the pair of legs 23 and 24. A grooved rail 25 is provided on the back surface of the first pedestal 21, and the attachment positions of the pair of legs 23 and 24 and the housing 51 of the light-projecting unit 5 can be changed along the rail 25.

[0020] Similarly, a handle 32 for carrying is attached to the surface of the second base 31. A pair of elongated, columnar legs 33, 34 are attached to the back surface of the second base 31 at a predetermined distance in the Y-axis direction. A housing 61 of the light receiving unit 6 is attached so as to be suspended between the pair of legs 33, 34 on the back surface of the second base 31. A grooved rail 35 is provided on the back surface of the second base 31, and the attachment positions of the pair of legs 33, 34 and the housing 61 of the light receiving unit 6 can be changed along the rail 35.

[0021] In order to fix the positional relationship between the light-projecting unit 5 attached to the first pedestal 21 and the light-receiving unit 6 attached to the second pedestal 31, the first pedestal 21 and the second pedestal 31 are connected to each other by two parallel, elongated, columnar horizontal frames 41, 42. In order to place the pair of legs 23, 24 of the first pedestal 21 and the pair of legs 33, 34 of the second pedestal 31 on edge surfaces 91a, 91b of the left and right side walls of the storage tank 91, respectively, the length of each of the horizontal frames 41, 42 is set to be shorter than the outer width of the storage tank 91 and to be the same as or slightly longer than the inner width (opening width) of the storage tank 91. As a result, the support frame 2 can be placed on the solder bath 9 so as to straddle the opening of the storage tank 91, and the light-projecting unit 5 attached to the first pedestal 21 of the support frame 2 and the light-receiving unit 6 attached to the second pedestal 31 can be disposed on both the left and right sides of the primary jet 101 and the secondary jet 102 (i.e., on both the left and right edges of the storage tank 91). The light-projecting unit 5 and the light-receiving unit 6 are disposed facing each other, and their positions in the Y-axis direction and the Z-axis direction are adjusted so that the band-shaped laser light emitted from the light-projecting unit 5 can be received by the light-receiving unit 6. For example, the position adjustment along the Y-axis direction can be achieved by moving the light-receiving unit 6 along the rails 35 relative to the light-projecting unit 5. The position adjustment along the Z-axis direction can be achieved by inserting a spacer between the housing 51 (61) of the light-projecting unit 5 (light-receiving unit 6) and the first pedestal 21 (second pedestal 31) and by changing the lengths of the legs 23, 24, 33, and 34.

[0022] The support frame 2 also has a locking structure for locking the support frame 2 placed on the solder bath 9 so that it does not move. Typically, the locking structure is realized by a clamping structure that clamps the entire reservoir bath 91. Specifically, the support frame 2 has a pair of plate-shaped first and second clamping portions 27 and 37. One end of the first clamping portion 27 is fastened to the outer surface of the first base 21 by a fastening member such as a screw. A pin 29 that protrudes inward is attached to the other end of the first clamping portion 27. One end of the second clamping portion 37 is fastened to the outer surface of the second base 31 by a fastening member such as a screw. A plunger 38 is attached to the other end of the second clamping portion 37 with the pin 39 protruding inward. By inserting a pair of pins 29, 39 provided on the left and right sides of the support frame 2 into bushings 93 provided on the left and right side walls of the storage tank 91, respectively, the support frame 2 placed on the solder tank 9 can be locked against movement in each axial direction. In this way, the jet height measuring device 1 of this embodiment can always fix the support frame 2 in the same position and orientation relative to the solder tank 9. In other words, the jet height measuring device 1 of this embodiment can measure the jet height or liquid level height while always positioning the light projector 5 and the light receiver 6 in the same position relative to the solder tank 9. This improves the reliability of the jet height and liquid level height and makes management easier than when the light projector 5 and the light receiver 6 are positioned in different positions relative to the solder tank 9 for each measurement. This also contributes to improving the quality of management of the jet height and liquid level height.

[0023] Furthermore, the support frame 2 includes an elevating device 7 that supports the shielding member 8 so that it can be raised and lowered along the Z-axis direction. Specifically, the elevating device 7 includes a rectangular parallelepiped rail block 71. The rail block 71 is fitted into a grooved rail 421 provided on the side of the cross section 42 of the support frame 2 and fastened with a fastening member such as a screw. That is, the rail block 71 is movable along the rail 421 in the X-axis direction. Therefore, by changing the position of the rail block 71 along the X-axis direction, the position to which the shielding member 8 is raised and lowered can be changed. A rail 73 is laid along the height direction (Z-axis direction) of the rail block 71. A slider block 75 is engaged with the rail 73. The shielding member 8 is fastened to the slider block 75 with a fastening member 87 such as a screw. The rail block 71 houses a drive mechanism (not shown), such as a motor, that drives the movement of the slider block 75. The drive mechanism is driven under the control of the control device 3, and the shielding member 8 is raised and lowered together with the slider block 75 along the rails 73. A stopper plate 89 is provided to prevent the shielding member 8 from unintentionally dropping to the liquid surface due to some cause, such as the stoppage of the drive mechanism. The stopper plate 89 is rotatably supported by a pole 88. The pole 88 is fitted into and fixed to a grooved rail 411 provided on the bottom surface of the cross section 41 of the support frame 2.

[0024] The shielding member 8 is a member that enables indirect measurement of the liquid level that cannot be directly measured by the photoelectric sensor because it is located below the detection range of the sensor. Specifically, the shielding member 8 has a highly heat-resistant plate-like float plate 81, a light-impermeable shielding rod 83 that is erected on the float plate 81, and a fixing plate 85 for fixing the shielding member 8 to the slider block 75. The length of the shielding rod 83 is set to a length that can block the band-like light irradiated from the light-projecting unit 5 when the shielding member 8 is placed on the liquid surface and floated.

[0025] 7 to 9, a method for measuring the height of the primary jet 101, the height of the secondary jet 102, and the height of the liquid surface using the jet height measurement device 1 according to this embodiment will be described. Figures 7, 8, and 9 show the state in which the height of the primary jet 101, the height of the secondary jet 102, and the height of the liquid surface are measured using the jet height measurement device 1 according to this embodiment, respectively.

[0026] 7, when measuring the height of the primary jet 101, only the jet pump for the primary jet 101 is driven, and the jet pump for the secondary jet 102 is stopped, so that only the primary jet 101 is generated in the storage tank 91. When the sensor is driven in this state, the band-like light irradiated from the light-emitting unit 5 toward the light-receiving unit 6 is blocked by the primary jet 101. Therefore, the height of the primary jet 101 can be measured based on the output of the light-receiving unit 6. The shielding member 8 is supported from the backside of the float plate 81 by a stopper plate 89 to prevent it from falling to the liquid surface.

[0027] As shown in Figure 8, when measuring the height of the secondary jet 102, only the jet pump for the secondary jet 102 is driven, and the jet pump for the primary jet 101 is stopped, so that only the secondary jet 102 is generated in the storage tank 91. When the sensor is driven in this state, the band-like light irradiated from the light-emitting unit 5 toward the light-receiving unit 6 is blocked by the secondary jet 102. Therefore, the height of the secondary jet 102 can be measured based on the output of the light-receiving unit 6. The shielding member 8 is supported from the backside of the float plate 81 by a stopper plate 89 to prevent it from falling to the liquid surface.

[0028] When the solder bath 9 is actually used, both the primary jet 101 and the secondary jet 102 are generated in the reservoir 91. Therefore, in order to measure the jet height of the primary jet 101 or the secondary jet 102 in a state as close as possible to the actual usage environment, when measuring the jet height of one jet, the other jet may be generated at a preset low output. Furthermore, since the secondary jet 102 is generally higher than the primary jet 101, when measuring the jet height of the secondary jet 102, the primary jet 101 may be generated at a normal output.

[0029] As shown in FIG. 9 , when measuring the liquid level of the solder bath 9, the jet pump for the primary jet 101 and the jet pump for the secondary jet 102 are stopped to prevent both the primary jet 101 and the secondary jet 102 from being generated in the storage tank 91. Then, after the user moves the stopper plate 89 to allow the shielding member 8 to move up and down, the drive mechanism of the lifting device 7 lowers the shielding member 8 and floats it on the liquid surface of the solder bath 9 under the control of the control device 3 based on the user's operation. With the shielding member 8 floating on the liquid surface, the drive mechanism of the lifting device 7 is stopped and controlled to a free state where no static torque is generated. Because the shielding member 8 is fixed to the slider block 75 of the lifting device 7, its movement in the forward, backward, left, and right directions is limited, and it is always floated at the same position (position in the XY plane) on the liquid surface by its own buoyancy alone. Because it is not subjected to a load in the Z-axis direction from the lifting device 7, the height of the shielding rod 83 of the shielding member 8 corresponds to the liquid level. In this way, the jet height measuring device 1 according to this embodiment floats the shielding member 8 at the same position on the liquid surface at all times, and can indirectly measure the liquid surface height of the solder bath 9. This improves the reliability of the liquid surface height measurement results and makes management easier, compared to when the shielding member 8 is placed in a different position for each measurement. This contributes to improving the quality of liquid surface height management.

[0030] The jet height measuring device 1 according to this embodiment can control the height of the primary jet 101, the height of the secondary jet 102, and the liquid level of the solder bath 9. By controlling the height of the primary jet 101, for example, if the height is lower than a reference value for the height of the primary jet 101, the output of the jet nozzle can be increased so that the height of the primary jet 101 reaches the reference value, thereby maintaining the quality of soldering performed by the primary jet 101. Similarly, by controlling the height of the secondary jet 102, for example, if the height is higher than a reference value for the height of the secondary jet 102, the output of the jet nozzle can be decreased so that the height of the secondary jet 102 reaches the reference value, thereby maintaining the quality of soldering performed by the secondary jet 102. Furthermore, by controlling the liquid level of the solder bath 9, for example, if the liquid level is lower than the reference value, solder can be replenished before the solder bath 9 is used. This prevents a shortage of molten solder during use and prevents a decrease in the efficiency of soldering using the solder bath 9.

[0031] The sensor included in the jet height measurement device 1 according to this embodiment is not limited to a transmission-type photoelectric sensor using an image sensor. For example, the sensor included in the jet height measurement device 1 according to this embodiment may be a photoelectric sensor using a light intensity discrimination method or a laser scanning method. The light intensity discrimination method is a method in which a strip of light is emitted from a light projecting unit, and the light is focused on a light receiving element by a lens in the light receiving unit, and fluctuations in the amount of light received by the light receiving element are measured as changes in the jet height and the liquid surface height. The laser scanning method is a method in which a thin beam of light is emitted from the light projecting unit while being scanned in the Z-axis direction. In this case, the light receiving unit may have multiple light receiving elements, or may have a single light receiving element that can move in conjunction with the scanning.

[0032] If the light-projecting unit 5 and the light-receiving unit 6 can be arranged on both the left and right sides of the opening of the storage tank 91, more specifically, if the light-projecting unit 5 can be arranged to the side of the jets (primary jets 101, secondary jets 102) generated in the storage tank 91 and in an orientation that allows it to irradiate a strip of light parallel to the direction of the jets, and if the light-receiving unit 6 can be arranged in a position opposite the light-projecting unit 5 across the jets, the support structure for the light-projecting unit 5 and the light-receiving unit 6 in the jet height measuring device 1 is not limited to this embodiment.

[0033] For example, the support frame supporting the light-projecting unit 5 and the support frame supporting the light-receiving unit 6 may be separate. Although the jet height measuring device 1 having two independent support frames is inferior in terms of ease of alignment compared to the jet height measuring device 1 according to the present embodiment, in which the light-projecting unit 5 and the light-receiving unit 6 are supported by a single support frame 2, the size of each component can be reduced, thereby improving portability.

[0034] Alternatively, the light-projecting unit 5 and the light-receiving unit 6 may be attached to two robots, or to two arms of a dual-arm robot, and the light-projecting unit 5 and the light-receiving unit 6 may be positioned by controlling the robot's motion. Specifically, a control device for controlling the robot executes a jet height measurement program to realize the robot-based jet height measurement method. That is, the control device controls the robot to position the light-projecting unit 5 to the side of the jet of molten solder stored in the solder bath 9, where the light-projecting unit 5 can irradiate a strip of light parallel to the direction of the jet, and to position multiple light-receiving units 6 facing the light-projecting unit 5 across the jet. Information representing the jet height is generated based on the outputs of the multiple light-receiving units 6. This jet height measurement method achieves the same effects as the present embodiment. The above-described jet height measurement method is not limited to being performed by a robot. For example, it may be performed manually by an operator.

[0035] Furthermore, the method of using a robot to position the light-projecting unit 5 and the light-receiving unit 6 eliminates the need for a structure to support the light-projecting unit 5 and the light-receiving unit 6, and thus prevents misalignment between the light-projecting unit 5 and the light-receiving unit 6 due to structural deterioration, distortion, or the like. Furthermore, the light-projecting unit 5 and the light-receiving unit 6 can be moved freely and independently, allowing for more accurate alignment. That is, the method of using a robot to position the light-projecting unit 5 and the light-receiving unit 6 requires a larger device (robot) than the method of supporting the light-projecting unit 5 and the light-receiving unit 6 with a single support frame 2 as in this embodiment, but it can improve the accuracy of alignment between the light-projecting unit 5 and the light-receiving unit 6. Furthermore, the method of supporting the light-projecting unit 5 and the light-receiving unit 6 with a robot does not require a specific size of solder bath, making it possible to accommodate solder baths of various sizes. Furthermore, in this embodiment, unless the mounting position of the support frame 2 relative to the solder bath 9 is changed, the jet height or liquid level height could only be measured at a single fixed point along the Y direction. However, if the light-projecting unit 5 and the light-receiving unit 6 are supported by a robot, the light-projecting unit 5 and the light-receiving unit 6 can be easily moved to any position along the Y-axis by the robot's operation, allowing measurement of the jet height or liquid level height at multiple positions along the Y-axis. By managing multiple jet heights corresponding to multiple positions along the Y-axis, it is possible to confirm whether the jet height is constant in the Y-axis direction. This makes it possible, for example, to always apply a jet of the same height to any position on a board transported by a conveyor. In this way, if the light-projecting unit 5 and the light-receiving unit 6 are supported by a robot, it is possible to manage the quality of soldering work using a jet-type solder bath.

[0036] In this embodiment, the lifting device 7 has been described as having a drive mechanism for raising and lowering the shielding member 8. However, even if the lifting device 7 does not have a drive mechanism, the same effect as this embodiment can be achieved. To measure the liquid level, the user manually moves the stopper plate 89 for preventing the shielding member 8 from falling, and then, while holding the shielding member 8, moves it downward along the rail 73 and gently places it on the liquid surface. Because the shielding member 8 is fixed to the slider block 75 of the lifting device 7, its movement in the forward, backward, left, and right directions is restricted, and it always floats at the same position (position in the XY plane) on the liquid surface. Furthermore, the shielding member 8 floats on the liquid surface solely by its own buoyancy, without receiving any external load from the lifting device 7 or the like. This allows the height of the shielding rod 83 of the shielding member 8 to be measured and managed as the liquid level. Although a configuration without a drive mechanism, as in this embodiment, requires more manual operation on-site than a configuration with a drive mechanism, it can reduce the overall weight of the support frame 2 and reduce costs.

[0037] The jet height measuring device 1 according to this embodiment can measure the jet height when a jet is being generated in the solder bath 9, and can measure the liquid level in the solder bath 9 by placing a shielding member 8 on the liquid surface when the solder bath 9 is in a stationary state where no jet is being generated. Therefore, the jet height measuring device 1 may be a measuring device that only measures the liquid level in the solder bath 9.

[0038] The following supplementary notes are further disclosed regarding this embodiment and its modifications. (Supplementary Note 1) The jet height measurement device 1 includes a light-projecting unit 5 that irradiates light from the side onto a jet of molten solder sprayed by a spray pump of a solder bath 9, a light-receiving unit 6 that faces the light-projecting unit 5 across the jet, and an information generating unit 114 that generates information representing the height of the jet based on the output of the light-receiving unit 6. (Supplementary Note 2) In the jet height measurement device 1 described in Supplementary Note 1, the light-projecting unit 5 emits a strip of light parallel to the height direction of the jet, the light-receiving unit 6 has multiple light-receiving elements arranged along the height direction, and the information generating unit generates information representing the height of the jet based on the output of each of the multiple light-receiving elements. (Supplementary Note 3) In the jet height measurement device 1 described in Supplementary Note 1 or Supplementary Note 2, a primary jet and a secondary jet are generated side by side in the solder bath 9, and the light-projecting unit 5 irradiates a strip of light in a direction that intersects the primary jet and the secondary jet. (Appendix 4) The jet height measuring device 1 described in any one of Appendices 1 to 3 further includes a shielding member 8 floating on the liquid surface of the molten solder. The shielding member 8 includes a float plate 81 and a shielding rod 83 standing on the float plate 81 and partially blocking light from reaching the light receiving unit 6 from the light projecting unit 5. (Appendix 5) The jet height measuring device 1 described in Appendix 4 further includes an elevation unit 7 that supports the shielding member 8 so that it can be raised and lowered relative to the liquid surface. (Appendix 6) In the jet height measuring device 1 described in Appendix 5, the elevation unit 7 has a structure 87 that limits movement of the shielding member 8 in a direction perpendicular to the elevation direction. (Appendix 7) The jet height measuring device 1 described in any one of Appendices 1 to 6 has a structure 29, 39 that is detachable from the solder bath 9. (Appendix 8) The jet height measurement method involves arranging a light-projecting unit 5 to the side of the jet of molten solder stored in a solder tank 9, in a position where it can irradiate a strip of light parallel to the direction of the jet, and arranging multiple light-receiving units 6 in positions opposite the light-projecting unit 5 across the jet, and generating information representing the height of the jet based on the outputs of the multiple light-receiving units 6.

[0039] Although the embodiments of the present disclosure have been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the invention or the concept and spirit of the present invention derived from the content of the claims and their equivalents. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

[0040] 1... Jet height measuring device, 3... Control device, 5... Light projecting unit, 6... Light receiving unit, 7... Lifting device, 8... Shielding member, 9... Solder bath, 10... Data / control bus, 11... Processor, 112... Determination unit, 114... Information generating unit, 12... RAM, 13... ROM, 14... Storage device, 15... Input controller, 16... Display controller, 18... Input device, 19... Display device, 2... Support frame, 21, 31... Base, 22, 32... Handle, 23, 24, 33, 34...legs, 25, 35...rails, 27, 37...clamping portion, 38...plunger, 29, 39...pin, 41, 42...horizontal portion, 51, 61...housing, 71...rail block, 73...rail, 74...slider block, 81...float plate, 83...shielding rod, 85...fixing plate, 88...pole, 89...stopper plate, 91...storage tank, 91a, 91b...edge surface, 93...bush, 101...primary jet, 102...secondary jet.

Claims

1. A light-emitting unit that illuminates the jet of molten solder ejected by the solder bath's ejection pump with light from the side, A light-receiving unit is positioned opposite the light-emitting unit, with the jet of water in between. An information generating unit that generates information representing the height of the jet based on the output of the light receiving unit, A jet height measuring device equipped with the following features.

2. The light-emitting unit emits a band of light parallel to the height direction of the jet, The light-receiving unit has a plurality of light-receiving elements arranged along the height direction, The information generation unit generates information representing the height of the jet based on the output of each of the plurality of light-receiving elements. The jet height measuring device according to claim 1.

3. In the aforementioned solder bath, a primary jet and a secondary jet are generated side by side. The light-emitting unit irradiates the light in a direction that crosses the primary jet and the secondary jet. A jet height measuring device according to claim 1 or claim 2.

4. The molten solder further comprises a shielding member that floats on the surface of the molten solder, The shielding member is, Float board and, The float plate is erected and includes a shielding rod that partially blocks the light from the light-emitting section to the light-receiving section, The jet height measuring device according to claim 1 or 2.

5. The shielding member is further supported by a lifting mechanism that allows it to move up and down relative to the liquid surface. The jet height measuring device according to claim 4.

6. The lifting mechanism has a structure that restricts the movement of the shielding member in a direction perpendicular to the direction of raising and lowering relative to the liquid surface. The jet height measuring device according to claim 5.

7. Having a structure that can be attached to and detached from the aforementioned solder bath, The jet height measuring device according to claim 1 or 2.

8. The light-emitting unit is positioned to the side of the jet of molten solder stored in the solder bath, and capable of emitting a band of light parallel to the direction of the jet. Multiple light-receiving units are positioned opposite the light-emitting unit, with the jet of water in between. Based on the output of the multiple light receiving units, information representing the height of the jet is generated. Jet term measurement method.