阅读说明：本技术 接地检测装置、电子元件安装机 (Grounding detection device and electronic component mounting machine ) 是由 石川贤三 于 2018-01-10 设计创作，主要内容包括：本发明的课题在于提供能够迅速地检测出接地的接地检测装置(6)、电子元件安装机(1)。接地检测装置(6)具备：光电传感器(60),向检测区域(A)投射光并接收来自检测区域(A)的光,在检测区域(A)被检测部(361a)与电子元件(P)相对于基板(B)的接地联动地相对移动；及接地判断部(7),基于来自光电传感器(60)的信号来判断有无接地。在非接地状态下,被检测部(361a)被配置于检测区域(A)。(The invention provides a grounding detection device (6) and an electronic component mounting machine (1) capable of rapidly detecting grounding. A ground fault detection device (6) is provided with: a photosensor (60) that projects light to and receives light from the detection area (A) and in which a detection target (361a) moves relative to the substrate (B) in conjunction with the grounding of the electronic component (P); and a grounding determination unit (7) that determines whether grounding is present or not based on a signal from the photoelectric sensor (60). In a non-grounded state, the detection target (361a) is disposed in the detection area (A).)

1. A ground fault detection device is provided with:

a photoelectric sensor that projects light to a detection region and receives the light from the detection region, and in the detection region, a detection target section moves relatively in conjunction with grounding of an electronic component with respect to a substrate; and

a grounding determination unit that determines whether the grounding is present or absent based on a signal from the photoelectric sensor,

the ground fault detection means is characterized in that,

setting the state of the electronic element not grounded on the substrate as a non-grounded state,

in the non-grounded state, the detection target portion is disposed in the detection area.

2. The ground detection device of claim 1,

setting a light receiving level of the photosensor in the non-grounded state as a reference level,

the grounding determination unit determines whether the grounding is present or absent based on a change in the light reception level with respect to the reference level.

3. The ground detection device of claim 2,

the ground fault determination unit updates the reference level at each predetermined timing.

4. The ground detection device of claim 3,

the predetermined said timing is said grounding.

5. An electronic component mounting machine includes:

the ground fault detection device of any one of claims 1 to 4; and

a suction nozzle for mounting the electronic component on the substrate,

the detected part is linked with the action of the suction nozzle.

Technical Field

The present disclosure relates to a ground detection device for detecting a ground of an electronic component with respect to a substrate, and an electronic component mounting machine including the ground detection device.

Background

Patent document 1 discloses an electronic component mounting apparatus that detects a ground (hereinafter, simply referred to as "ground" as appropriate) of an electronic component with respect to a substrate using an optical fiber sensor. When the electronic component attracted to the suction nozzle is grounded on the substrate, the light receiving amount of the light receiving part of the optical fiber sensor is reduced. When the amount of received light is equal to or less than a predetermined threshold value, the optical fiber sensor transmits a ground contact detection signal to the control unit.

Disclosure of Invention

Problems to be solved by the invention

However, in the case of a sensor of a conventional electronic component mounting machine, although an electronic component is not grounded on a substrate due to oscillation of a sensor output or the like, the sensor may erroneously detect the ground. Therefore, in order to avoid erroneous detection, a dead zone is secured near the detection zone of the sensor in the ungrounded state (state where the electronic component is not grounded on the substrate). However, if the dead zone is set, even if the substrate is actually grounded to the electronic component, the electronic component mounting apparatus cannot detect the grounding until the suction nozzle passes through the dead zone and enters the detection zone. Therefore, the grounding cannot be detected quickly. Therefore, an object of the present disclosure is to provide a ground fault detection device and an electronic component mounting machine capable of quickly detecting a ground fault.

Means for solving the problems

In order to solve the above problem, a ground fault detection device according to the present disclosure includes: a photoelectric sensor that projects light to a detection region and receives the light from the detection region, and in the detection region, a detection target portion moves relative to a substrate in conjunction with grounding of an electronic component; and a ground fault determination unit configured to determine whether or not the ground fault is present based on a signal from the photosensor, wherein a state in which the electronic component is not grounded on the substrate is set to a non-grounded state, and the detection target unit is disposed in the detection region in the non-grounded state.

Here, the "detection target portion is arranged in the detection region in the non-grounded state" includes a mode in which the detection target portion is entirely contained in the detection region in the non-grounded state, a mode in which a part of the detection target portion is contained in the detection region in the non-grounded state, and a mode in which the detection target portion and the detection region are connected in the non-grounded state.

In order to solve the above problem, an electronic component mounting apparatus according to the present disclosure includes the ground detection device and a suction nozzle for mounting the electronic component on the board, and the detected portion is interlocked with an operation of the suction nozzle.

Effects of the invention

According to the ground detection device and the electronic component mounting machine of the present disclosure, the detected portion is already arranged in the detection area in the non-grounded state. Therefore, in the non-grounded state, at least a part of the light has been blocked by the detected part. Therefore, it is not necessary to secure an insensitive area beside the detection area. This enables the grounding to be detected quickly.

Drawings

Fig. 1 is a right side view of an electronic component mounting machine as an embodiment of the electronic component mounting machine of the present disclosure.

Fig. 2 is a block diagram of the electronic component mounting machine.

Fig. 3 is a sectional view of the mounting head of the electronic component mounting machine.

Fig. 4 is a sectional view in the direction IV-IV of fig. 3.

Fig. 5 is a sectional view of the holder and the suction nozzle of the electronic component mounting machine.

Fig. 6 is a schematic view of a ground detection method performed by the ground detection apparatus of the electronic component mounting machine.

Detailed Description

Embodiments of the ground fault detection device and the electronic component mounting apparatus according to the present disclosure will be described below. Fig. 1 shows a right side view of the electronic component mounting machine of the present embodiment. Fig. 2 shows a block diagram of the electronic component mounting machine. Fig. 3 shows a sectional view of the mounting head of the electronic component mounting machine. Fig. 4 shows a sectional view in the direction IV-IV of fig. 3. Fig. 5 shows a cross-sectional view of the holder and the suction nozzle of the electronic component mounting machine. In detail, fig. 5A shows a cross-sectional view of the holder and the suction nozzle in a grounded state (1 thereof). Fig. 5B shows a cross-sectional view of the holder and the suction nozzle in the grounded state (2 thereof).

The "grounded state" is a state in which the electronic component is grounded on the substrate. In fig. 1, this is illustrated through the housing 391 of the module 3. The holder 36 and the suction nozzle 37 in fig. 5A and 5B are the "holder 36 and the suction nozzle 37" on the front side of the "holder 36 and the suction nozzle 37" in fig. 3 (in the grounded state) and the "holder 36 and the suction nozzle 37" on the front side of the "holder 36 and the suction nozzle 37" on the rear side (in the non-grounded state).

< Structure of electronic component mounting machine >

First, the structure of the electronic component mounting apparatus according to the present embodiment will be described. As shown in fig. 1 and 2, the electronic component mounting apparatus 1 includes: base 2, module 3, tape feeder (component supply device) 4, equipment tray 5, and ground fault detection device 6.

The base 2 is disposed on the floor (not shown) of the factory. The module 3 is mounted on the base 2. As shown in fig. 1 and 3 to 5B, the module 3 includes: the substrate transfer device 30, the XY robot 31, the mounting head 32, the eight holders 36, the eight suction nozzles 37, the first spring 380, the second spring 381, the third spring 382, the substrate lifting device 390, and the housing 391.

As shown in fig. 1, the housing 391 constitutes an outer shell of the module 3. The substrate transport apparatus 30 can transport the substrate B from the left side (upstream side) to the right side (downstream side). The substrate lifting device 390 can lift the substrate B from the conveyor belt of the substrate conveyor 30.

As shown in fig. 1 to 2, the XY robot 31 includes: a Y-axis (front-rear axis) slider 310, a Y-axis motor 311, an X-axis (left-right axis) slider 312, an X-axis motor 313, a pair of left and right Y-axis guide rails 314, and a pair of upper and lower X-axis guide rails 315. The pair of left and right Y-axis guide rails 314 are disposed on the upper wall lower surface of the housing 391. The Y-axis slider 310 is attached to the pair of left and right Y-axis rails 314 so as to be slidable in the front-rear direction. The upper and lower pair of X-axis guide rails 315 are disposed on the front surface of the Y-axis slider 310. The X-axis slider 312 is attached to the pair of upper and lower X-axis guide rails 315 so as to be slidable in the left-right direction.

As shown in fig. 1, the mounting head 32 is mounted to the X-axis slider 312. Therefore, the mounting head 32 can be moved in the front-rear left-right direction by the XY robot 31. As shown in fig. 3, the mounting head 32 includes: a cover 320, a pair of front and rear elevating units 33, a revolving unit 34, and a rotating unit 35.

As shown in fig. 3, the cover 320 constitutes a housing of the mounting head 32. The front and rear pair of elevating portions 33 are disposed to face each other at 180 ° about a revolution axis Q (a revolution axis of the eight nozzles 37). The elevating unit 33 includes a Z-axis (vertical axis) motor 330 and a ball screw unit 331. The ball screw portion 331 includes a shaft portion (fixed portion) 331a and a nut portion (movable portion) 331 b. The Z-axis motor 330 is mounted to the housing 320. The shaft 331a is coupled to a rotation shaft of the Z-axis motor 330. The shaft 331a extends in the vertical direction. The nut portion 331b is circumferentially attached to the shaft portion 331a via a plurality of balls (not shown). The nut portion 331b is provided with a recess (power transmission portion) 332.

As shown in fig. 3 to 4, the revolution part 34 includes: a Q-axis (revolution axis) motor 340, a first revolution gear 341, a second revolution gear 342, a revolution axis 343, a rotation plate 344, and eight sleeves 345. The Q-axis motor 340 is attached to the cover 320 via a bracket (not shown). The first common gear 341 is coupled to the rotation shaft of the Q-axis motor 340. The second revolution gear 342 meshes with the first revolution gear 341. The rotating plate 344 is disposed below the second common rotation gear 342 at a predetermined interval. The common shaft 343 couples the common second gear 342 and the rotating plate 344. The eight sleeves 345 are arranged at 45 ° intervals about the revolution axis Q. The sleeve 345 has a cylindrical shape with a short axis extending in the vertical direction. The sleeve 345 is embedded in the rotating plate 344.

As shown in fig. 3 to 4, the rotation unit 35 includes: an R-axis (rotation axis) motor 350, a first rotation gear 351, a second rotation gear 352, and a third rotation gear 353. The R-axis motor 350 is attached to the cover 320 via a bracket (not shown). The first rotation gear 351 is coupled to a rotation shaft of the R-axis motor 350. The second rotation gear 352 meshes with the first rotation gear 351. The second rotation gear 352 has an annular shape. The third rotation gear 353 is connected to a lower side of the second rotation gear 352. The third rotation gear 353 has a cylindrical shape. The common rotation shaft 343 penetrates the second rotation gear 352 and the third rotation gear 353 in the vertical direction.

As shown in fig. 3, 5A, and 5B, the eight holders 36 are inserted into the sleeves 345, respectively. The holder 36 includes a clad portion 360 and a core portion 361. The cladding 360 is movable in the vertical direction with respect to the sleeve 345. The clad portion 360 includes: an outer cylinder member 360a, a convex portion (power transmission portion) 360c, a holder gear 360d, and a pin (guided portion) 360 e. A step surface 360b facing downward is disposed radially inward of the outer cylindrical member 360 a. The convex portion 360c is disposed on the outer peripheral surface of the outer tube member 360 a. The convex portion 360c is vertically engageable with the concave portion 332. The holder gear 360d is disposed on the outer peripheral surface of the outer tube member 360 a. As shown in fig. 4, the holder gear 360d meshes with the third rotation gear 353. As shown in fig. 5A and 5B, the pin 360e is disposed at the lower end of the outer cylinder member 360 a. The pin 360e penetrates the outer tube member 360a in the diameter direction.

As shown in fig. 5A and 5B, in the grounded state, the cladding 360 is movable relative to the core 361 in the vertical direction by a pressing stroke S to be described later. Fig. 5A shows a state in which the cladding portion 360 is positioned at the top dead center of the pressing stroke S. Fig. 5B shows a state in which the cladding portion 360 is at the bottom dead center of the pressing stroke S.

As shown in fig. 5A and 5B, the core 361 includes, from the upper side to the lower side: a detection target 361a, a first shaft member 361b, a second shaft member 361c, a first inner cylinder member 361e, and a second inner cylinder member 361 g. The detection target 361a protrudes upward from the outer tube member 360 a. The first shaft member 361b is coupled to the lower side of the detected part 361 a. The first shaft member 361b is inserted through the outer tube member 360 a. The second shaft member 361c is coupled to a lower side of the first shaft member 361 b. The enlarged diameter portion 361d is disposed at the lower end of the second shaft member 361 c. The first inner cylindrical member 361e accommodates the lower portion of the second shaft member 361 c. A radially inner side of the first inner cylindrical member 361e is provided with a reduced diameter portion 361 f. The enlarged diameter portion 361d engages with the reduced diameter portion 361f from below. The second inner tube member 361g is connected to the lower side of the first inner tube member 361 e. The second inner cylindrical member 361g is provided with a pair of long holes (guide portions) 361 h. The pair of long holes 361h are disposed so as to face each other at 180 ° about the rotation axis (revolution axis of the suction nozzle 37) R. The long hole 361h extends in the vertical direction.

As shown in fig. 5A and 5B, the eight nozzles 37 are respectively housed in the second inner cylinder member 361 g. The suction nozzle 37 is provided with a long hole (guide portion) 370. The long hole 370 penetrates the suction nozzle 37 in the diameter direction. The long hole 370 extends in the up-down direction. The pair of long holes 361h and 370 have the same height. The pin 360e is inserted through the pair of long holes 361h and 370. The pin 360e is movable in the vertical direction along the pair of long holes 361h and 370 in accordance with the pressing stroke S. The suction unit 371 is disposed at the lower end of the suction nozzle 37. The suction portions 371 can suck and release the electronic components P by air pressure supplied through an unillustrated gas passage.

As shown in fig. 5A and 5B, the first spring 380 is disposed between the detection target portion 361a and the outer cylinder member 360 a. The first spring 380 biases the outer cylindrical member 360a, i.e., the clad portion 360, downward with respect to the detected portion 361a, i.e., the core portion 361. The second spring 381 is disposed between the stepped surface 360b and the first inner cylinder member 361 e. The second spring 381 urges the stepped surface 360b, i.e., the clad portion 360, upward with respect to the first inner cylinder member 361e, i.e., the core portion 361. The third spring 382 is disposed between the holder gear 360d and the sleeve 345. The third spring 382 urges the holder gear 360d, i.e., the cladding 360, upward with respect to the sleeve 345, i.e., the rotating plate 344.

As shown in fig. 2 to 3, the ground fault detection device 6 includes: a pair of front and rear photosensors 60, and a control device (ground fault determination unit) 7. The photosensor 60 is a reflective photosensor. The photosensor 60 is disposed on the nut portion 331 b. The photoelectric sensor 60 is movable in the vertical direction together with the nut portion 331 b. The photoelectric sensor 60 includes a light projector and a light receiver, not shown. The light projector can project light to the detection section 361 a. The light receiver can receive the reflected light from the detected portion 361 a. As shown in fig. 5A and 5B, a detection area a is set near the photosensor 60 in the horizontal direction (on the side of the detection section 361 a).

As shown in fig. 2, the control device 7 includes: an input/output interface 70, an arithmetic unit 71, and a storage unit 72. The input/output interface 70 is connected to the photosensor 60. The input/output interface 70 is connected to the X-axis motor 313, the Y-axis motor 311, the Z-axis motor 330, the Q-axis motor 340, and the R-axis motor 350 via a drive circuit (not shown).

As shown in fig. 1, the equipment tray 5 is mounted on the front side of the housing 391. The tape feeder 4 is mounted to the apparatus tray 5. The suction nozzle 37 takes out the electronic component P from the tape feeder 4 and mounts the electronic component P on the substrate B at a predetermined mounting coordinate.

< actions of mounting head, holder, and suction nozzle >

Next, the operations of the mounting head, the holder, and the suction nozzle of the electronic component mounting apparatus according to the present embodiment will be described. As shown in fig. 1 to 2, when the mounting head 32 is moved in the horizontal direction, the control device 7 drives the Y-axis motor 311 and the X-axis motor 313. When the control device 7 drives the Y-axis motor 311, the Y-axis slider 310, that is, the mounting head 32 moves in the front-rear direction along the Y-axis guide 314. When the control device 7 drives the X-axis motor 313, the X-axis slider 312, that is, the mounting head 32 moves in the left-right direction along the X-axis guide rail 315.

As shown in fig. 2 to 3, the control device 7 drives the Q-axis motor 340 when the eight holders 36 are rotated (revolved) about the revolution axis Q. In addition, the suction nozzle 37 also moves together with the holder 36. When the control device 7 drives the Q-axis motor 340, the first revolution gear 341 rotates, and the second revolution gear 342, the common shaft 343, and the rotating plate 344 rotate integrally. That is, the eight sleeves 345, that is, the eight holders 36 rotate about the revolution axis Q. Therefore, two holders 36 opposed to each other at 180 ° among the eight holders 36 can be set at the elevation position (a position where the convex portion 360c engages with the concave portion 332 as in the front and rear pair of holders 36 in fig. 3).

As shown in fig. 2 to 4, when the holder 36 is rotated (revolved) about the revolution axis R, the controller 7 drives the R-axis motor 350. In addition, the suction nozzle 37 also moves together with the holder 36. When the controller 7 drives the R-axis motor 350, the rotation first gear 351 rotates, and the rotation second gear 352 and the rotation third gear 353 rotate integrally. The third rotation gear 353 meshes with the holder gear 360 d. Therefore, when the rotation third gear 353 rotates, the holder gear 360d, that is, the holder 36 rotates about the rotation axis R.

As shown in fig. 2 to 3, when the holder 36 at the up-down position is lowered, the control device 7 drives the Z-axis motor 330. In addition, the suction nozzle 37 also descends together with the holder 36. When the control device 7 drives the Z-axis motor 330, the shaft portion 331a rotates about its own axis. Therefore, the nut portion 331b, that is, the recess portion 332 descends with respect to the shaft portion 331 a. Therefore, the holder 36 engaged with the convex portion 360c of the concave portion 332, that is, the up-down position, is lowered against the urging force of the third spring 382. The electronic component P sucked to the suction nozzle 37 is grounded to the substrate B.

The retainer 36 is set with a pressing stroke S. As shown in fig. 5A (a state in which the cladding portion 360 is positioned at the top dead center of the pressing stroke S) and fig. 5B (a state in which the cladding portion 360 is positioned at the bottom dead center of the pressing stroke S), even if the electronic component P is grounded on the substrate B, the cladding portion 360 can be lowered with respect to the suction nozzle 37 and the core portion 361 against the urging forces of the third spring 382 and the second spring 381 by consuming at least a part of the pressing stroke S. Therefore, the impact when the electronic component P is grounded on the substrate B can be alleviated.

< operation of electronic component mounting machine >

Next, an operation of the electronic component mounting apparatus according to the present embodiment in substrate production will be described. As shown in fig. 1, the control device 7 first drives the substrate transport device 30 to carry the substrate B in from the left-hand (upstream) substrate working machine (e.g., screen printer, substrate appearance inspection machine, electronic component mounting machine, etc.). Subsequently, the controller 7 drives the substrate lifting/lowering device 390 to lift the substrate B to a predetermined mounting height. Subsequently, controller 7 sequentially sucks a plurality of electronic components P from tape feeder 4 by using all suction nozzles 37.

Specifically, as shown in fig. 1 to 4, first, the controller 7 drives the Q-axis motor 340 to set the desired holder 36 and the desired suction nozzle 37 at the elevation position. Subsequently, the control device 7 drives the Z-axis motor 330 to lower the holder 36 and the suction nozzle 37, and the electronic component P is sucked from the tape feeder 4 by the suction nozzle 37. By repeating this operation of the number of the arranged suction nozzles 37, the electronic components P are mounted on all the suction nozzles 37.

Then, the control device 7 drives the Y-axis motor 311 and the X-axis motor 313 to transport the plurality of electronic components P to the substrate B. Then, the controller 7 sequentially mounts the plurality of electronic components P on the plurality of mounting coordinates of the substrate B by the same operation as that at the time of suction of the electronic components P.

After the electronic component P is mounted, the controller 7 drives the substrate lifting/lowering device 390 to lower the substrate B. Then, the controller 7 drives the substrate transfer device 30 to discharge the substrate B to the right-side (downstream-side) substrate working machine.

< grounding detection method >

Next, a method of detecting the ground fault performed by the ground fault detecting device of the present embodiment will be described. The ground detection method is executed when the suction nozzle 37 mounts the electronic component P on the board B in the series of operations of the electronic component mounter 1.

Fig. 6 is a schematic diagram illustrating a ground fault detection method performed by the ground fault detection apparatus according to the present embodiment. Step S2 corresponds to fig. 5A (a state in which the cladding 360 is positioned at the top dead center of the pressing stroke S), and step S4 corresponds to fig. 5B (a state in which the cladding 360 is positioned at the bottom dead center of the pressing stroke S). However, in the ground fault detection method described below, steps S1 to S3 are executed. Step S4 is not performed.

The ground fault detection method includes a reference value setting step and a ground fault determination step. As shown in step S1, the reference value setting step is executed in a non-grounded state (specifically, a state in which the horizontal conveyance of the electronic component P by the XY robot 31 is completed and a state before the lowering of the holder 36 and the suction nozzle 37 is performed, as in the holder 36 and the suction nozzle 37 on the rear side in fig. 3). As shown in fig. 2, in the reference value setting step, the control device 7 detects the light acceptance rate of light from the light receiver of the photosensor 60. The light acceptance is included in the concept of "light acceptance level" of the present invention.

If it is assumed that the detected part 361a does not enter the detection area a (for example, if the insensitive area F is secured below the detection area a and the detected part 361a is disposed below the insensitive area F in the ungrounded state as schematically shown in step S1), the total amount of light from the light projector does not enter the light receiver. This state (hereinafter, appropriately referred to as "initial state") is set to 0%. When it is assumed that the detection target 361a enters the entire detection area a (for example, when the detection target 361a is disposed over the entire length of the detection area a in the vertical direction as shown in step S4), the entire amount of the reflected light from the detection target 361a enters the light receiver. This state (hereinafter, appropriately referred to as "final state") is set to 100%.

In contrast, actually, as shown in step S1, the upper end of the detected part 361a enters the detection area a in the non-grounded state. In the initial value setting step, the control device 7 shown in fig. 2 detects the light receiving rate of the light receiver in the non-grounded state, and sets the reference level a 1. For example, when the initial state is 0% and the final state is 100%, and the light receiving rate of the light receiver in the non-grounded state is 10%, the control device 7 sets the 10% as the reference level a 1. The control device 7 sets the reference level a1 to 100%, and sets the threshold a2 to 110%, for example.

As shown in steps S1 to S3, the grounding determination step is executed when the non-grounding state is switched to the grounding state. That is, when the holder 36 and the suction nozzle 37 are lowered. In the grounding determination step, the control device 7 shown in fig. 2 drives the Z-axis motor 330 to lower the holder 36 and the suction nozzle 37 relative to the mounting head 32 shown in fig. 3. Then, the control device 7 continuously detects the light receiving rate of the light from the light receiver of the photosensor 60.

When the holder 36 is lowered and the electronic component P is grounded on the board B, the suction nozzle 37 and the core 361 are immediately stopped from being lowered (steps S1 to S2). However, the clad portion 360 continues to descend together with the nut portion 331b and the photosensor 60 shown in fig. 5A (step S3). Therefore, the suction nozzle 37 and the core 361 are relatively raised with respect to the cladding 360. When the core portion 361 rises relative to the cladding portion 360, the detection target portion 361a rises relative to the detection region a. Therefore, the light receiving rate of the light receiver of the photosensor 60 increases. When the light reception rate reaches the threshold value a2, the control device 7 determines that the electronic component P is grounded to the substrate B. The control device 7 stops the Z-axis motor 330 to stop the lowering of the holder 36 and the suction nozzle 37. The controller 7 releases the grounded electronic component P from the suction nozzle 37, and drives the Z-axis motor 330 to raise the holder 36 and the suction nozzle 37.

Then, the control device 7 sets the next holder 36 and the suction nozzle 37 (the electronic component P is sucked) right above the next mounting coordinate. Then, the control device 7 executes the reference value setting step and the grounding judgment step. In this way, the control device 7 repeatedly executes the above-described ground detection method for the number of electronic components P held by the mounting head 32.

< Effect >

Next, the operation and effects of the ground fault detection device and the electronic component mounting apparatus according to the present embodiment will be described. According to the ground fault detection device 6 of the present embodiment, as shown in step S1 in fig. 6, the upper end of the detected part 361a has entered the detection area a in the non-ground fault state. Therefore, in the non-grounded state, at least a part of the light from the light projector is already reflected by the detection section 361a and enters the light receiver. Therefore, grounding can be detected more quickly than in the case where the insensitive area F (schematically shown in step S1) is secured below the detection area a shown in fig. 6 and the detected part 361a is disposed below the insensitive area F in the non-grounding state.

In addition, when the dead zone F is secured below the detection area a, even if the electronic component P is actually grounded to the board B, the ground fault detection device 6 cannot detect the ground fault until the detection object 361a rises in the dead zone F and enters the detection area a. Therefore, while the detected part 361a passes through the dead zone F, a pressing force is applied from the nut part 331B to the electronic component P on the substrate B via the holder 36 and the suction nozzle 37. In this regard, according to the ground fault detection device of the present embodiment, it is not necessary to set the dead zone F. Therefore, the application of an excessive pressing force to the electronic component P can be suppressed.

As shown in fig. 6, the ground fault detector 6 of the present embodiment has only a slight time lag D between the timing when the non-grounded state is actually switched to the grounded state (step S2) and the timing when the controller 7 determines that the non-grounded state is switched to the grounded state (step S3). Therefore, the grounding can be detected quickly. Further, the control device 7 can determine that the ground is connected in the state of step S3. Therefore, as shown by the broken line in fig. 6, the electronic component P is not pressed from step S3 to step S4 (until the entire pressing stroke S is consumed). Therefore, the application of an excessive pressing force to the electronic component P can be suppressed.

In the conventional ground fault detection device, the output of the photosensor 60 in the non-grounded state is set to "0", for example, and the output of the photosensor 60 in the grounded state is set to "1", for example, and the ground fault is determined digitally (intermittently, binary, yes/no). In contrast, according to the ground fault detection device 6 of the present embodiment, as shown in fig. 6, the control device 7 determines whether or not a ground fault is present based on a change in the light reception rate from the reference level a 1. That is, the output of the photosensor 60 can be captured in an analog manner (continuously, obliquely) to detect the ground. Therefore, erroneous detection of the ground can be suppressed.

In addition, according to the ground fault detection device 6 of the present embodiment, the control device 7 updates the reference level a1 for each ground fault. Therefore, even when the heights of the detected parts 361a in the non-grounded state shown in step S1 of fig. 6 are different between the plurality of suction nozzles 37 arranged in the single mounting head 32, in other words, even when the degrees of entrance of the detected parts 361a into the detection area a are different, a detection error is not easily generated.

The light receiving rate of the light receiver varies depending on environmental factors such as temperature fluctuation and the state of an amplifier (not shown). Therefore, if the reference level a1 is fixed, the detection accuracy is degraded. In this regard, according to the ground fault detection device 6 of the present embodiment, the control device 7 updates the reference level a1 for each ground fault. Therefore, a decrease in detection accuracy due to environmental factors can be suppressed.

In addition, according to the ground fault detector 6 of the present embodiment, the controller 7 updates the threshold a2 in accordance with the update of the reference level a 1. That is, the threshold a2 is not an "absolute" threshold, but a "relative" threshold with respect to the reference level a 1. In this regard, the occurrence of the detection error and the deterioration of the detection accuracy can be suppressed.

< others >

The embodiments of the ground fault detection device and the electronic component mounting apparatus according to the present disclosure have been described above. However, the embodiment is not particularly limited to the above embodiment. It is needless to say that the present invention can be implemented in various modifications and improvements that can be made by those skilled in the art.

The control device 7 of the electronic component mounting apparatus 1 may not double as the ground determination unit of the ground detection device 6. That is, the control device 7 and the ground fault determination unit may be independent of each other. The value of the reference level a1 with respect to the initial state is not particularly limited. The light reception rate in the non-grounded state shown in fig. 4A may be set to the reference level a 1. In the non-grounded state shown in fig. 4A, the upper end of the detection target 361a may be aligned with the lower end of the detection area a. In this case, when the initial state is set to 0%, the reference level a1 is similarly set to 0%.

The timing of updating the reference level a1 is not particularly limited. For example, the reference level a1 may be updated for each electronic component conveying operation of the XY robot 31 shown in fig. 1 (an operation in which the XY robot 31 conveys the electronic component P from the tape feeder 4 to the substrate B in the horizontal direction), each production completion of one substrate B, each power input of the electronic component mounter 1, each replacement of the suction nozzle 37, each replacement adjustment of the type of the substrate B to be produced, and the like. In addition, the reference level a1 may be fixed.

The value of the threshold value a2 with respect to the reference level a1 is not particularly limited. When the threshold a2 is made to approach the reference level a1 (for example, when the reference level a1 is 100% and the threshold a2 is 110% or less), the ground fault can be detected quickly. When the threshold a2 is set to be distant from the reference level a1 (for example, when the reference level a1 is set to 100% and the threshold a2 is set to 150% or more), erroneous detection of the ground fault can be suppressed. The threshold value a2 may be fixed.

The positions of the detection section 361a and the photosensor 60 are not particularly limited. The members that do not move when the pressing stroke S is consumed in the grounded state (e.g., the core 361, the shaft 331a, the suction nozzle 37, the substrate transport device 30, the cover 320, the rotating plate 344, etc.) are "fixed-side members". In addition, the member (for example, the clad portion 360 and the nut portion 331b) that moves when the pressing stroke S is consumed in the grounded state is referred to as a "movable-side member". In this case, the detection portion 361a may be disposed on one of the fixed-side member and the movable-side member, and the photosensor 60 may be disposed on the other. For example, the detection object 361a may be disposed on the stationary member and the photosensor 60 may be disposed on the movable member. Conversely, the detection section 361a may be disposed on the movable-side member and the photoelectric sensor 60 may be disposed on the fixed-side member. That is, the photoelectric sensor 60 may be configured to detect a change in the relative positional relationship between the fixed-side member and the movable-side member when the pressing stroke S is consumed. The kind of the photosensor 60 is not particularly limited. For example, the photoelectric sensor 60 of a transmission type, a reflection type (a retro-reflection type, a diffuse reflection type), or the like can be used. In addition, a non-contact sensor other than the photoelectric sensor may be used.

When the transmission type photosensor 60 is used, the light emitter and the light receiver of the photosensor 60 may be disposed on both sides in the horizontal direction with the detection section 361a interposed therebetween. In this case, the light projector and the light receiver may be attached to the nut portion 331b via the bracket. Hereinafter, a method of setting the reference level a1 and the threshold value a2 in the reference value setting step of the ground fault detection method in the case of using the transmission type photosensor 60 will be described with reference to fig. 6. In the reference value setting step (step S1), the control device 7 detects the light receiving rate of the light from the light receiver of the photosensor 60. The light acceptance is included in the concept of "light acceptance level" of the present invention. That is, if the detected part 361a does not enter the detection area a, the entire amount of light from the projector enters the light receiver. This state (hereinafter, appropriately referred to as "initial state") is set to 100%. In contrast, actually, as shown in step S1, the upper end of the detected part 361a enters the detection area a in the non-grounded state. In the initial value setting step, the control device 7 detects the light receiving rate of the light receiver in the non-grounded state, and sets the reference level a 1. For example, when the initial state is 100% and the light receiving rate of the light receiver in the non-grounded state is 90%, the control device 7 sets the 90% to the reference level a 1. The controller 7 sets the reference level a1 to 100%, for example, 90% as the threshold a 2.

The number of arrangement of the suction nozzles 37 with respect to the single mounting head 32 is not particularly limited. The number of the suction nozzles 37 may be single or plural. The mounting head 32 may not include at least one of the rotation unit 34 and the rotation unit 35. The mounting head 32 may have a single elevating unit 33. The projection 360c may have a flange shape. The arrangement of the concave portion 332 and the convex portion 360c may be reversed. That is, the concave portion 332 may be disposed in the cladding portion 360 and the convex portion 360c may be disposed in the nut portion 331 b. It is sufficient if power can be transmitted from the nut portion 331b to the cladding portion 360. The nut portion (movable portion) 331b may be moved in the vertical direction by a mechanism other than the ball screw portion 331.

The ground fault detection device 6 may detect the ground fault based on the amount of leakage of a fluid (gas (air, nitrogen), liquid (oil), or the like), for example. Specifically, the gas passage is arranged so that the amount of air leakage increases when the suction nozzle 37 rises relative to the cladding 360. In addition, in the non-grounded state shown in step S1 in fig. 6, a predetermined amount of air has been caused to leak, and this leakage amount is set to the reference level a 1. The reference level a1 was set to 100%, and 110% was set to the threshold a 2. In this way, when the electronic component P is switched from the non-grounded state to the grounded state and the leakage amount is equal to or greater than the threshold value a2, the control device 7 can determine that the electronic component P is grounded. In this way, the ground fault detection device 6 may detect a ground fault based on a signal related to a detected value (a flow rate, a mass, a distance, a current value, a voltage value, or the like) that continuously changes from the non-grounded state to the grounded state.

Description of the reference numerals

1: electronic component mounting machine, 2: base station, 3: module, 4: tape feeder, 5: equipment tray, 6: ground fault detection device, 7: control device (grounding determination unit), 30: substrate conveying apparatus, 31: XY robot, 32: a mounting head, 33: lifting part, 34: revolution portion, 35: rotation portion, 36: cage, 37: suction nozzle, 60: photosensor, 70: input-output interface, 71: calculation unit, 72: storage unit, 310: y-axis slider, 311: y-axis motor, 312: x-axis slider, 313: x-axis motor, 314: y-axis guide, 315: x-axis guide, 320: cover, 330: z-axis motor, 331: ball screw portion, 331 a: shaft portion, 331 b: nut portion, 332: recess, 340: q-axis motor, 341: common first gear, 342: common second gear, 343: common shaft, 344: rotating plate, 345: sleeve, 350: r-axis motor, 351: first gear for rotation, 352: second gear for rotation, 353: third gear for rotation, 360: clad portion, 360 a: outer cylinder member, 360 b: step surface, 360 c: convex portion, 360 d: cage gear, 360 e: pin, 361: core, 361 a: detected portion, 361 b: first shaft member, 361 c: second shaft member, 361 d: diameter-enlarged portion 361 e: first inner tube member, 361 f: reduced diameter portion, 361 g: second inner tube member, 361 h: long hole, 370: long hole, 371: adsorption section, 380: first spring, 381: second spring, 382: third spring, 390: substrate lifting device, 391: a housing, A: detection area, B: a substrate, D: time lag, F: insensitive area, P: electronic component, Q: revolution axis, R: rotation axis, S: pressing stroke, a 1: reference level, a 2: and (4) a threshold value.