Linear motor, mounting-related device, and linear motor control method

Abstract

This linear motor comprises: a stator member that includes a stator; a movable element that moves by being guided by the stator member; a detection unit that detects the state of the stator member; and a control unit that controls the driving force for the movable element, taking into consideration the value detected by the detection unit.

Description

[Technical Field]

[0001] This specification discloses a linear motor, a mounting-related device, and a method for controlling the linear motor. [Background technology]

[0002] A conventional motor control device has been proposed that calculates the temperature of a motor coil in a motor based on the temperature measured by a temperature sensor inside the device, and connects an inverter that supplies power to the motor to a power supply if this temperature is below a predetermined reference temperature, and cuts off the inverter and power supply if this temperature is equal to or higher than the reference temperature (see, for example, Patent Document 1). This device is said to be able to set a cooling period according to the state of the motor and shorten the cooling period. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2013 / 187985 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, a linear motor is an example of a driving device in which a mover is guided by a stator. With this linear motor, continued driving can cause the components to overheat, making it impossible to obtain the desired output. While the aforementioned Patent Document 1 disconnects the inverter from the power supply depending on the internal temperature of the motor control device, this type of output reduction is not taken into consideration. Thus, there is a need for a linear motor that can provide a more appropriate driving force.

[0005] The present disclosure has been made in consideration of such problems, and has as its main object to provide a linear motor, a mounting-related device, and a method for controlling a linear motor that can obtain a more appropriate driving force. [Means for solving the problem]

[0006] The linear motor, mounting-related device, and linear motor control method disclosed in this specification employ the following means to achieve the above-mentioned main object.

[0007] The linear motor of the present disclosure comprises: a stator member including a stator; a mover that is guided by the stator member and moves; a detection unit for detecting a state of the stator member; a control unit that controls the driving force of the mover by taking into account the detection value of the detection unit; It is equipped with the following.

[0008] In this linear motor, the drive force of the mover is controlled taking into account the values ​​detected by a detector that detects the state of the stator member. In linear motors, if the temperature rises during operation, the drive force can decrease due to thermal demagnetization, but by taking the state of the stator member into account, this linear motor can obtain a more appropriate drive force. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic explanatory diagram showing an example of a mounting system 10. [Figure 2] FIG. 2 is an explanatory diagram showing the outline of the configuration of the mounting section 20. [Figure 3] FIG. 2 is an explanatory diagram showing the outline of the configuration of a linear motor 30. [Figure 4] FIG. 4 is an explanatory diagram showing an example of correction information 53 stored in a storage unit 52. [Figure 5] 10 is a flowchart showing an example of a control processing routine. [Figure 6] FIG. 10 is an explanatory diagram showing an example of another correction information 53B stored in the storage unit 52. DETAILED DESCRIPTION OF THE INVENTION

[0010] This embodiment will be described below with reference to the drawings. FIG. 1 is a schematic diagram illustrating an example of a mounting system 10 according to the present disclosure. FIG. 2 is a diagram illustrating an outline of the configuration of a mounting unit 20. FIG. 3 is a diagram illustrating an outline of the configuration of a linear motor 30. FIG. 4 is a diagram illustrating an example of correction information 53 stored in a storage unit 52. FIG. 4A is a relationship diagram between the detected temperature (°C) and the current correction value (A), FIG. 4B is a relationship diagram between the detected magnetic flux (Wb) and the current correction value (A), FIG. 4C is a relationship diagram between the detected temperature (°C) and the torque constant correction value (N / A), and FIG. 4D is a relationship diagram between the detected magnetic flux (Wb) and the torque constant correction value (N / A). In this embodiment, the left-right direction (X-axis), the front-back direction (Y-axis), and the up-down direction (Z-axis) are as shown in FIGS. 1 and 2.

[0011] Mounting system 10 is configured, for example, as a production line in which mounting devices 15 that place components P on a substrate S as an object to be processed are arranged in the transport direction of the substrate S. Here, the object to be processed is described as a substrate S, but is not particularly limited as long as it is something on which components can be mounted, and it may also be a base material with a three-dimensional shape. As shown in FIG. 1, this mounting system 10 is configured to include a printing device 11, a print inspection device 12, a mounting device 15, a mounting inspection device 16, a loader 18, and a reflow device (not shown).

[0012] The printing device 11 is a device that prints a viscous fluid such as solder paste on a substrate S. The printing device 11 includes a drive unit that raises and lowers a squeegee that prints the solder, and a drive unit that slides the squeegee in the printing direction. The print inspection device 12 is a device that inspects the printed solder and the condition of the substrate S. The print inspection device 12 includes a drive unit that moves an imaging unit that captures images in the X and Y directions. The mounting device 15 is a device that picks up components P and arranges them on the substrate S. As shown in FIG. 2, the mounting device 15 includes a mounting unit 20 and a component supply unit 21. The mounting unit 20 includes a mounting head 22 and a collection member 23. The mounting head 22 moves in the X and Y directions by a drive unit. The collection member 23 is a nozzle or the like that picks up components P, and is raised and lowered along the Z axis by a linear motor 30 that serves as a drive unit. The mounting inspection device 16 is a device that inspects the condition of components P arranged on the substrate S. The mounting inspection device 16 is equipped with a drive unit that moves an imaging unit that captures images in the X and Y directions. The loader 18 is a mobile work device that automatically replaces feeders and moves by a drive unit along an X-axis rail 19 in front of the mounting system 10. The loader 18 has a drive unit that clamps the feeder and moves it back and forth, and a drive unit that moves the feeder up and down. The reflow device is a device that reflows a board S on which solder is printed and components P are arranged. The linear motor 30 may be used as a drive unit for any of the devices in the mounting system 10 described above. Here, we will mainly explain the case where the linear motor 30 is a drive unit that drives the lifting and lowering of the collection member 23.

[0013] The linear motor 30 is configured as a shaft linear motor, which is a drive unit that drives the mover 35 in a predetermined drive direction along the shaft 31. As shown in Fig. 3, the linear motor 30 includes the shaft 31, the mover 35, a control unit 50, a servo amplifier 51, and a memory unit 52. The linear motor 30 is a drive device that moves the collection member 23 in the vertical direction, but in Fig. 3, the drive direction of the linear motor 30 is shown horizontally.

[0014] The shaft 31 is a stator member that includes a stator 32. The shaft 31 also functions as a guide that leads the mover 35 in a predetermined drive direction. The shaft 31 includes a force control region A that requires a large load in the predetermined drive direction, and a normal control region B that requires a small load relative to the force control region A. In the linear motor 30, the force control region A is included in the lower end region of the shaft 31 that biases and holds the collection member 23 in a downwardly pressed state. Note that the force control region A is not limited to the end of the stator member, and can be any region, such as the center, as long as it is a region that requires force control.

[0015] The shaft 31 is a cylindrical member having a cavity in its central axis, and a detection unit 33 is disposed inside the detection unit 33. A detection wiring inserted into the cavity is connected to the detection unit 33, and the detection wiring is connected to the control unit 50. The detection unit 33 may be one or more of a temperature sensor and a magnetic sensor. The detection unit 33 is disposed at a position where it detects the force control region A of the shaft 31. The detection unit 33 may detect the state of the shaft 31 as a stator member, or may detect the state of the stator 32. Furthermore, one detection unit 33 may be disposed inside the shaft 31, or two or more detection units 33 may be disposed inside the shaft 31. When multiple detection units 33 are disposed on the shaft 31, they may be a single type of sensor (e.g., a temperature sensor) or multiple types of sensors (e.g., a temperature sensor and a magnetic sensor). Here, the detection unit 33 is a temperature sensor disposed in the force control region A and detects the temperature of the shaft 31 in the force control region A.

[0016] The mover 35 is a member that is engaged with or disposed on a driven object and is guided by the shaft 31 to move in the drive direction. The mover 35 has a coil 40 inside a case. The coil 40 receives power from a servo amplifier 51 via wiring and functions as an electromagnet. Wiring 46 includes a power supply wiring and a ground wiring connected to the coil 40, and is drawn out from the mover 35. The power supply wiring of the wiring 46 is connected to the servo amplifier 51. The wiring 46 is guided by a guide member (not shown) so as not to interfere with the movement of the mover 35.

[0017] The control unit 50 is configured as a controller centered on a CPU, and is responsible for controlling the entire linear motor 30 device. This control unit 50 receives control commands from a higher-level control device of the mounting device 15 and operates based on these control commands. The control unit 50 outputs control signals to a servo amplifier 51, while also receiving detection signals from the detection unit 33. The servo amplifier 51 is a driving device that outputs driving power to the coil 40 based on the control signal from the control unit 50. The servo amplifier 51 may, for example, receive current position information from an encoder of the mover 35, and based on this information, output driving power required to move to a target position.

[0018] The storage unit 52 is, for example, a flash memory, and stores various data including processing programs. The storage unit 52 stores correction information 53 used to correct the power supplied to the mover 35. The correction information 53 includes a correspondence relationship between the state of the stator 32 and stator components and a correction value for the driving force of the mover 35. As shown in FIG. 4A, the correction information 53 may be a current correction value determined based on a tendency that the higher the temperature detected by the detection unit 33, which is a temperature sensor, the greater the driving force. Alternatively, as shown in FIG. 4B, the correction information 53 may be a current correction value determined based on a tendency that the lower the magnetic flux detected by the detection unit 33, which is a magnetic sensor, the greater the driving force. Furthermore, as shown in FIG. 4C, the correction information 53 may be a torque constant correction value determined based on a tendency that the higher the temperature detected by the detection unit 33, which is a temperature sensor, the greater the driving force. 4D, the correction information 53 may be such that the torque constant correction value is determined based on the tendency that the smaller the magnetic flux detected by the detection unit 33, which is a magnetic sensor, the greater the driving force. In the linear motor 30, any of the above correspondence relationships may be adopted depending on the type of the detection unit 33.

[0019] In the linear motor 30, as the mover 35 is driven, the coil 40 may generate heat, which may be transferred to the shaft 31, causing the temperature of the shaft 31 to rise. A detector 33 is disposed inside the shaft 31 to detect the state of the shaft 31, thereby detecting the heat generated by the coil 40 and demagnetization caused by the heat. If demagnetization occurs in the linear motor 30, it may not be possible to output the required driving force, so the controller 50 uses the correction information 53 to correct the supplied power.

[0020] Next, we will first explain the production process of the board S in the mounting system 10 configured as described above. After loading the board S, the printing device 11 brings the board S into contact with the screen mask M, and then uses a drive unit to lower the squeegee and slide it back and forth to print solder paste onto the board S. After the printing process, the printing device 11 uses a drive unit to raise the squeegee and transport the board S outside the device. After loading the printed board S, the print inspection device 12 uses a drive unit to move the imaging unit, performs imaging processing of the board S with the imaging unit, inspects the print pattern through image processing, and transports the board S outside the device. After loading the inspected board S, the mounting device 15 moves the mounting head 22 over the component supply unit 21, lowers the pickup member 23 to pick up the component P, and then moves the mounting head 22 over the board S to place the component P in a predetermined position on the board S. When the placement of the components P is complete, the mounting device 15 transports the board S out of the device. After the mounting inspection device 16 transports the board S on which the components P have been placed, it moves the imaging unit using a drive unit, performs imaging processing of the board S with the imaging unit, inspects the placement state of the components P through image processing, and transports the board S out of the device. In this way, the mounting system 10 drives each drive unit of each device to produce the board S, which is the object to be processed. In the mounting system 10, a linear motor 30 is used in one or more drive units of each device, and mounting-related processing related to the mounting process of placing the components P on the board S, which is the object to be processed, is performed by driving and controlling the linear motor 30.

[0021] Next, drive control using the detector 33 in the linear motor 30 will be described. The detector 33 in the linear motor 30 mainly detects the temperature of the shaft 31 and outputs the detected value. FIG. 5 is a flowchart showing an example of a control processing routine executed by the controller 50 of the linear motor 30. This routine is stored in the memory 52 and executed after the linear motor 30 is started. When this routine starts, the controller 50 determines whether the mover 35 is within the force control region A (S100). The controller 50 acquires the position of the mover 35 on the shaft 31 based on the value of an encoder (not shown). If the mover 35 is not within the force control region A, the controller 50 executes standard drive processing (S110). In this drive processing, a control command is output to the servo amplifier 51 to supply the coil 40 with the power required to move the mover 35 to the target position. In response to this control command, the servo amplifier 51 outputs drive power to the coil 40 based on the content of the control command.

[0022] On the other hand, if the mover 35 is within the force control region A in S100, the control unit 50 acquires a detection value from the detection unit 33 (S120) and determines whether the acquired detection value is within the standard range (S130). The standard range is set to a standard temperature range in which the linear motor 30 can operate without requiring output correction or the like. If the detection value is within the standard range, the control unit 50 acquires a correction value corresponding to the detected temperature, which is the acquired detection value, using the correction information 53 (S160) and executes a drive process taking this correction value into account (S170). The control unit 50 may, for example, acquire a current correction value ( FIG. 4A ) that corrects the output current value, or may acquire a torque constant correction value ( FIG. 4C ) that corrects the output torque value. In the drive process, the control unit 50 outputs a control command to the servo amplifier 51 to supply the coil 40 with output power obtained by adding the correction value to the power required to move the mover 35 to the target position. In response to this control command, the servo amplifier 51 outputs output power to the coil 40 based on the content of the control command.

[0023] On the other hand, if the detected value is not within the standard range in S130, the control unit 50 determines whether the detected value is within the allowable range in which the mover 35 can be driven (S140). This allowable range is empirically determined as a warning range that is outside the standard range but lower than the range of conditions (e.g., temperature range) of the shaft 31 that require an emergency stop. If the detected value is within the allowable range, the control unit 50 outputs a warning to the control device of the mounting device 15 that the temperature of the coil 40 exceeds the standard range, and executes the processing from S160 onwards. Upon receiving the warning, the control device of the mounting device 15 displays the contents of the warning on the operation panel as a warning screen. The operator checks this warning screen and understands that the temperature of the linear motor 30 is rising.

[0024] On the other hand, if the detected value is not within the allowable range in S140, the control unit 50 determines that the coil 40 is in an overheated state, temporarily suspends the supply of power to the coil 40 to cool the coil 40, and outputs information to the control device of the mounting device 15 that the linear motor 30 has been temporarily stopped (S180). When the control device of the mounting device 15 acquires the information about the temporary stop, it displays the information on the operation panel as a temporary stop screen. The worker checks this temporary stop screen and understands that the linear motor 30 is in an overheated state. After the linear motor 30 is temporarily stopped in S180, once the coil 40 has cooled, the detected value returns to the allowable range in S140 and the drive process is resumed.

[0025] After S180, S170, or S110, the control unit 50 determines whether the processing of the linear motor 30 has completely finished based on whether production has been completed (S190), and if production has not been completed, executes the processing from S100 onwards. On the other hand, if production is completed in S190, the control unit 50 ends this routine. In this way, in the force control region A, the linear motor 30 can be driven more accurately and safely while correcting the driving force based on the detection value of the detection unit 33 and preventing overheating.

[0026] Here, the correspondence between the components of this embodiment and the components of the present disclosure will be clarified. In this embodiment, the shaft 31 corresponds to the stator member, the stator 32 corresponds to the stator, the mover 35 corresponds to the mover, the detection unit 33 corresponds to the detection unit, and the control unit 50 corresponds to the control unit. Also, the printing device 11, the print inspection device 12, the mounting device 15, the mounting inspection device 16, the loader 18, and the reflow device correspond to mounting-related devices. Note that in this embodiment, an example of a control method for a linear motor of the present disclosure is also clarified by explaining the operation of the mounting system 10.

[0027] The linear motor 30 described above includes a shaft 31 serving as a stator member including a stator 32, a mover 35 that moves along the shaft 31, a detector 33 that detects the state of the shaft 31 including the stator 32, and a controller 50 that controls the driving force of the mover 35 by taking into account the value detected by the detector 33. In this linear motor 30, the driving force of the mover 35 is controlled by taking into account the value detected by the detector 33 that detects the state of the shaft 31. Generally, in linear motors, if there is a temperature rise during operation, the driving force may decrease due to thermal demagnetization. However, in this linear motor 30, a more appropriate driving force can be obtained by taking into account the state of the shaft 31 serving as a stator member.

[0028] Furthermore, the detector 33 is disposed at a position that detects the force control region A of the shaft 31, and the controller 50 controls the mover 35 taking into account the detection value of the detector 33 in the force control region A, so that the linear motor 30 can obtain a more appropriate driving force in the force control region A where a driving force is required. The detector 33 is also a temperature sensor, and the controller 50 controls the mover 35 so that the higher the temperature detected by the temperature sensor, the greater the driving force. This linear motor 30 can obtain a more appropriate driving force in temperature conditions that change the driving force, such as thermal demagnetization. Furthermore, the stator member is the shaft 31, and the detector 33 is disposed inside the shaft, so that the linear motor 30 can obtain a more appropriate driving force in this shaft linear motor structure.

[0029] Furthermore, the mounting device 15 as a mounting-related device is equipped with the above-mentioned linear motor 30 as a drive unit, and therefore is able to obtain a more appropriate driving force. Furthermore, the control method for the linear motor 30 is a control method for a linear motor 30 that is equipped with a shaft 31 as a stator member including a stator 32, and a mover 35 that moves along with the shaft 31, and includes a detection step (S120) of detecting the state of the shaft 31, and a step (S170) of controlling the driving force of the mover 35 by taking into account the value detected in the detection step. With this control method for the linear motor 30, a more appropriate driving force can be obtained by taking into account the state of the shaft 31.

[0030] It goes without saying that the linear motor, mounting-related device, and linear motor control method of the present disclosure are in no way limited to the above-described embodiments, and can be implemented in various forms as long as they fall within the technical scope of the present disclosure.

[0031] For example, in the above-described embodiment, the detector 33 is primarily a temperature sensor. However, this is not limited thereto, and the detector 33 may be a magnetic sensor. In this case, the control unit 50 may control the mover 35 so that the smaller the detected magnetic flux from the magnetic sensor, the greater the driving force. This linear motor 30 can obtain a more appropriate driving force, for example, in a situation where the magnetic field state changes, such as a demagnetized state. The linear motor 30 may also include a temperature sensor and a magnetic sensor. In this case, the control unit 50 may prioritize the detected value that requires greater correction when the detection results from the temperature sensor and the magnetic sensor differ. Alternatively, the control unit 50 may use the temperature sensor as a temporary suspension condition and the magnetic sensor to correct the supplied power. The greater the number and types of detectors 33, the more precise the correction control can be performed.

[0032] In the above-described embodiment, the correction information 53 controls the mover 35 using a correction value that increases the driving force as the temperature detected by the temperature sensor increases, but this is not particularly limited. Furthermore, the correction information 53 controls the mover 35 using a correction value that increases the driving force as the magnetic flux detected by the magnetic sensor decreases, but this is not particularly limited. FIG. 6 is an explanatory diagram showing an example of another correction information 53B stored in the memory unit 52. FIG. 6A is a relationship diagram between the detected temperature and the current correction value, FIG. 6B is a relationship diagram between the detected magnetic flux and the current correction value, FIG. 6C is a relationship diagram between the detected temperature and the supplied power (W), and FIG. 4D is a relationship diagram between the detected magnetic flux (Wb) and the supplied power (W). As shown in FIGS. 6A and 6B, the control unit 50 may control the mover 35 so that the driving force increases as the temperature detected by the temperature sensor increases. That is, the correction value may have a region where the driving force remains unchanged and a region where the driving force decreases. Even with this correction value, the mover 35 can be driven with a greater driving force as the detected temperature increases overall. 6B, which uses a magnetic sensor, is equivalent. Furthermore, in the above-described embodiment, the driving force of the mover 35 is controlled using a correction value, but this is not particularly limited to this, and as shown in FIGS. 6C and 6D, the mover 35 may be controlled by acquiring the supply power corresponding to the detection value. In this linear motor 30, too, a more appropriate driving force can be obtained by taking into account the state of the shaft 31 as a stator member.

[0033] In the above-described embodiment, the detector 33 is disposed in the force control region A of the shaft 31, but this is not particularly limited, and the detector 33 may also be disposed in the normal control region B, and the mover 35 may be controlled taking into account the detected value also in the normal control region B. In this linear motor 30, too, a more appropriate driving force can be obtained by taking into account the temperature state or magnetic flux state of the shaft 31 as a stator member.

[0034] In the above-described embodiment, the linear motor 30 is used as a drive unit for the mounting unit 20, but is not limited to this and may be used as a drive unit for any of the mounting devices 15, or as a drive unit for any of the devices included in the mounting system 10. Furthermore, the linear motor 30 may also be used as a drive unit for machine tools that perform various processing operations other than the mounting system 10, manufacturing devices such as 3D printers, and the like.

[0035] In the above-described embodiment, the linear motor 30 has been described as a shaft linear motor in which the stator member including the stator 32 serves as the shaft 31, but the stator member is not particularly limited to a shaft-shaped stator member. For example, the linear motor may be a linear motor having a long, flat stator member, or a linear motor having long, flat stator members sandwiched from both ends of the mover 35.

[0036] In the above-described embodiment, the present disclosure has been described as being applied to the linear motor 30. However, the present disclosure may also be applied to a manufacturing method for a processing object, or as a program for causing a computer to execute each step of this manufacturing method. Furthermore, while the present disclosure has been described as being applied to the linear motor 30 and as a manufacturing method for a processing object, the present disclosure is not limited thereto. The present disclosure may also be applied to a control method for a linear motor 30 that drives a mover 35 based on a detection value from a detector 33 disposed on a stator member, or as a program for causing a computer to execute each step of this control method. Note that this control method may employ various aspects of the linear motor 30 described above, or may include additional steps that realize each function of the linear motor 30 described above. In this control method, a more appropriate driving force can be obtained by taking into account the state of the stator member. [Industrial Applicability]

[0037] The present disclosure is applicable to the technical field of devices having driving parts. [Explanation of symbols]

[0038] 10 Mounting system, 11 Printing device, 12 Printing inspection device, 15 Mounting device, 16 Mounting inspection device, 18 Loader, 19 X-axis rail, 20 Mounting unit, 21 Component supply unit, 22 Mounting head, 23 Picking member, 30 Linear motor, 31 Shaft, 32 Stator, 33 Detection unit, 35 Movable element, 40 Coil, 46 Wiring, 50 Control unit, 51 Servo amplifier, 52 Memory unit, 53 Correction information, A Force control area, B Normal control area, P Component, S Board.

Claims

1. a stator member including a stator; a mover that is guided by the stator member and moves; a detection unit for detecting a state of the stator member; a control unit that controls the driving force of the mover by taking into account the detection value of the detection unit, the detection unit is a temperature sensor, The control unit controls the mover so that the higher the temperature detected by the temperature sensor, the greater the driving force.

2. the stator member is a shaft; The linear motor according to claim 1 , wherein the detection unit is disposed inside the shaft.

3. a stator member including a stator; a mover that is guided by the stator member and moves; a detection unit for detecting a state of the stator member; a control unit that controls the driving force of the mover by taking into account the detection value of the detection unit, the stator member is a shaft; The linear motor, wherein the detection unit is disposed inside the shaft.

4. the detection unit is a magnetic sensor, 4. The linear motor according to claim 1, wherein the control unit controls the mover so that the smaller the magnetic flux detected by the magnetic sensor, the greater the driving force.

5. A mounting-related device related to a mounting process for placing components on a processing target, A linear motor according to any one of claims 1 to 4 is provided as a drive unit. Mounting related equipment.

6. A method for controlling a linear motor including a stator member including a stator and a mover that moves while being guided by the stator member, comprising: (a) detecting a temperature of the stator member by a temperature sensor; (b) controlling the driving force of the mover by taking into account the detection value in the step (a), In the step (b), the mover is controlled so that the driving force increases as the temperature detected by the temperature sensor increases.

7. A method for controlling a linear motor including a stator member including a stator and a mover that moves while being guided by the stator member, comprising: (a) detecting a state of the stator member by a detector; (b) controlling the driving force of the mover by taking into account the detection value in the step (a), the stator member is a shaft; A method for controlling a linear motor, wherein the detection unit is disposed inside the shaft.

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