Position detector and linear conveying system

Abstract

A position detector (5) comprises a position-detection-specific magnet (6) that can be installed on a rotor (4) moving along a conveying path (2) comprising a stator (3); a position detection unit (7) that can be installed on the conveying path (2) and that detects a magnetic field generated by the position-detection-specific magnet (6); a plurality of magnetic shielding elements (8) that can be arranged and installed with a gap (10) in a first direction (A), which is a direction of movement of the rotor (4) along the conveying path (2), and are designed to provide shielding against a magnetic flux that runs from a rotor magnet (4c) of the rotor (4) and coils (3b) of the stator (3) to the position detection unit (7);and a gap-specific magnetic shielding element (9) which closes the gap (10) between adjacent magnetic shielding elements of the magnetic shielding elements (8), wherein the gap-specific magnetic shielding element (9) is designed to provide shielding against the magnetic flux;

Description

Area

[0001] The present disclosure relates to a position detector that detects a slider position and a linear conveying system. background

[0002] A conventional linear servo motor includes a slider and a stator. The slider is configured to include a base and a slider magnet attached to the base for generating a magnetic field to move the slider. The stator is configured to include a stator core and a coil attached to the stator core for generating a magnetic field to move the slider. In the linear servo motor, the stator coil generates the magnetic field when energized. This magnetic field creates a driving force, thereby moving the slider. The linear servo motor is installed in systems such as linear conveying systems for conveying articles.

[0003] Linear conveying systems equipped with linear servo motors generally employ a magnetic position detector that detects the position of the slider. The position detector includes a position-detecting magnet installed on the slider to generate a magnetic field for position detection, and a position detection unit that detects the magnetic field generated by the position-detecting magnet.

[0004] When a magnetic flux generated by the rotor magnet and the coil interferes with the position detection unit, the position detector cannot accurately detect the magnetic field generated by the position detection-specific magnet, resulting in the problem of deteriorated detection accuracy of the rotor.

[0005] Such a problem is reduced by a technique disclosed in Patent Literature 1. In the disclosed technique, a magnetic shielding member disposed between a stator and position detection units serves as a shield against a magnetic flux flowing from coils to the position detection units. Citation listPatent literature

[0006] Patent Literature 1: PCT, International Publication No. 2021 / 124 439 Brief description of the inventionProblem to be solved by the invention

[0007] When the slider moves a long distance, as in a linear conveying system, it is necessary to provide a stator and a magnetic shielding member, each divided into a plurality of parts, and to arrange and install the plurality of stators in a conveying direction when assembling the linear conveying system. Even if the plurality of magnetic shielding members are arranged and installed without gaps, a gap will occur between adjacent magnetic shielding members due to unavoidable size and assembly tolerances, etc. The magnetic flux generated by the slider magnet and the coil passes through the gap toward the position detection unit, thus interfering with the position detection unit. For this reason, there is room for improvement in the technique disclosed in Patent Literature 1 regarding improving the accuracy of slider position detection.

[0008] The present disclosure has been made in view of the above, and an object of the present disclosure is to obtain a position detector configured to prevent a magnetic flux generated by a rotor magnet and coils from disturbing a position detection unit through a gap and to improve its rotor position detection accuracy over a conventional position detector. Means of solving the problem

[0009] To solve the above problem and achieve the object, a position detector according to the present disclosure includes: a position detection-specific magnet installable on a mover for moving along a conveying path including a stator; and a position detection unit installable on the conveying path, which detects a magnetic field generated by the position detection-specific magnet.The position detector according to the present disclosure further comprises a plurality of magnetic shielding members that are arrangeable and installable with a gap in a first direction, which is a moving direction of the rotor along the conveying path, wherein the magnetic shielding members are configured to provide shielding against a magnetic flux passing from a rotor magnet of the rotor and coils of the stator to the position detection unit; and a gap-specific magnetic shielding member that closes the gap between adjacent magnetic shielding members of the magnetic shielding members, wherein the gap-specific magnetic shielding member is configured to provide shielding against the magnetic flux. Effects of the invention

[0010] The position detector according to the present disclosure has the effect of preventing the magnetic flux generated by the rotor magnet and the coils from disturbing the position detection unit through the gap, and improving its rotor position detection accuracy compared with a conventional position detector. Short description of the drawings Fig. 1 is a plan view showing an entire linear conveying system according to a first embodiment. Fig. 2 is a sectional view showing the linear conveying system according to the first embodiment. Fig. 3 is a plan view showing the linear conveying system according to the first embodiment. Fig. 4 is a side view showing the linear conveying system according to the first embodiment. Fig. 5 is an explanatory diagram showing an effect of the linear conveyance system according to the first embodiment. Fig. 6 is a side view showing a linear conveying system according to a second embodiment. Fig. 7 is a side view showing a linear conveying system according to a third embodiment. Fig. 8 is a side view showing a linear conveying system according to a fourth embodiment. Fig. 9 is a side view showing a linear conveying system according to a fifth embodiment. Fig. 10 is a side view showing a linear conveying system according to a sixth embodiment. Description of embodiments

[0011] With reference to the drawings, a detailed description is given below of position detectors and linear conveying systems according to embodiments. First embodiment.

[0012] Fig. 1 is a plan view showing an entire linear conveying system 1 according to a first embodiment. Fig. Figure 2 is a sectional view showing the linear conveying system 1 according to the first embodiment. The linear conveying system 1 is a system that uses a linear servo motor to convey articles. As shown in Fig. 1, the linear conveying system 1 comprises a plurality of runners 4 and a conveying path 2 which comprises a plurality of stators 3. As shown in Fig. 2, the linear conveying system 1 also includes a position detector 5. Although not shown, the linear conveying system 1 includes a controller that controls movement of the sliders 4.

[0013] Fig. 2 shows a section perpendicular to the transport directions, which are directions of movement of the runners 4 along the transport path 2. In the following description, the transport directions, which are the directions of movement of the runners 4 along the transport path 2 and the directions leading to the drawing area of Fig. 2 are perpendicular are referred to as the first directions A. Directions that are orthogonal to the first directions A are referred to as the second directions B. Directions that are orthogonal to the first directions A and the second directions B are referred to as the third directions C. In the following description, the second directions B are also defined as the vertical directions. In the following description, the second direction B is defined to include an upward direction towards the top of the drawing and a downward direction towards the bottom of the drawing. For the purpose of explanation, in Fig. 2 Sections of a stator core 3a of the stator 3 and a housing 4a and a base 4b of the rotor 4 are hatched, all of which will be described later.

[0014] The Fig. The transport path 2 shown in Figure 1 has a path shape with straight and curved sections; however, the shape can be changed as needed. For example, the shape of the transport path 2 can be straight and curved, can be another shape with a straight section and a curved section, or can be divided into several paths at one point. As shown in Fig. 2, the conveying path 2 includes the stator 3. Although not shown, the conveying path 2 includes a base member and brackets, wherein the base member holds the stators 3, position detection units 7 (described later), and magnetic shielding elements 8 (described later), and the brackets are arranged between the base member, the stators 3, the position detection units 7, and the magnetic shielding elements 8. During assembly of the conveying path 2, the stators 3, the position detection units 7, and the magnetic shielding elements 8 can be attached to the same bracket, and this bracket can then be attached to the base member.Alternatively, during the assembly of the conveying path 2, the stators 3 may be attached to one of the brackets, the position detection units 7 and the magnetic shielding elements 8 may be attached to the other bracket, and then the brackets may be attached to the base member.

[0015] Fig. 3 is a plan view showing the linear conveying system 1 according to the first embodiment. Fig. 4 is a side view showing the linear conveying system 1 according to the first embodiment. As shown in Fig. 3, the stators 3 are divided in the first direction A. The stators 3 shown in the drawing are two in number; however, this example is not intended to limit the number of stators 3. The plurality of stators 3 are arranged and installed in the first direction A. The adjacent stators 3 are arranged continuously. Each stator 3 includes the stator core 3a and a plurality of coils 3b.

[0016] The stator core 3a includes a core back 3c and a plurality of teeth 3d. The core back 3c extends in the first direction A. The plurality of teeth 3d protrude from an end of the core back 3c facing the rotor 4 in the third direction C. The plurality of teeth 3d are arranged at intervals in the first direction A.

[0017] Each of the plurality of coils 3b is provided on one of the plurality of teeth 3d. In other words, the plurality of coils 3b are formed of wires that are each wound around one of the plurality of teeth 3d.

[0018] The runners 4 are components that move along the conveyor path 2 and, together with the stators 3, form the linear servo motor. As shown in Fig. 2, each rotor 4 comprises the housing 4a, the base 4b and a rotor magnet 4c.

[0019] The housing 4a is a plate-shaped element that supports the base 4b. The housing 4a extends in the second direction B. The housing 4a extends further in the second direction B than the stators 3.

[0020] The base 4b is a plate-shaped member attached to a surface of the housing 4a facing the stator 3. The base 4b is arranged near one end of the housing 4a in the second direction B. The position of the base 4b and the position of the stator 3 in the second direction B are aligned. The base 4b faces the stator 3 in the third direction C. The base 4b extends in the second direction B.

[0021] The rotor magnet 4c is a component that generates a magnetic field for moving the rotor 4. The rotor magnet 4c is, for example, a permanent magnet. The rotor magnet 4c is attached to a surface of the base 4b facing the stator 3. The rotor magnet 4c is attached to the housing 4a via the base 4b. A position of the rotor magnet 4c and the position of the stator 3 in the second direction B are aligned. The rotor magnet 4c faces the stator 3 in the third direction C and is arranged away from the stator 3 in the third direction C. The rotor magnet 4c extends in the second direction B.

[0022] The rotor magnet 4c includes a magnetic field generating surface 4d where the magnetic field is generated. In the present embodiment, the magnetic field generating surface 4d of the rotor magnet 4c is the surface facing the stator 3 and extending in the second direction B. The magnetic field generating surface 4d is a flat surface orthogonal to the third direction C. An electric current flows through the coil 3b, thereby generating a magnetic field. This magnetic field causes a driving force on the rotor magnet 4c, allowing the rotor 4 to move. As shown in Fig. 3, a plurality of rotor magnets 4c are mounted on the single base 4b. The plurality of rotor magnets 4c are arranged at intervals in the first direction A. The number of rotor magnets 4c shown in the drawing is three; however, this example is not intended to limit the number of rotor magnets 4c. The plurality of rotor magnets 4c need not be arranged at intervals.

[0023] As in Fig. 2, the position detector 5 includes a position detection-specific magnet 6, the position detection unit 7, the magnetic shielding member 8, and a gap-specific magnetic shielding member 9. The position detector 5 is a device that detects a position of each slider 4.

[0024] The position detection-specific magnet 6 is a magnet that generates a magnetic field for detecting the position of the rotor 4. The position detection-specific magnet 6 is, for example, a measuring magnet with multiple magnetic poles. The position detection-specific magnet 6 is installed on the rotor 4. The position detection-specific magnet 6 is attached to the surface of the housing 4a facing the stator 3. The position detection-specific magnet 6 is positioned near an opposite end of the housing 4a in the second direction B, the opposite end being opposite the end near which the base 4b is arranged. The position detection-specific magnet 6 is arranged away from the stator 3 in the second direction B. The position detection-specific magnet 6 is arranged away from the rotor magnet 4c in the second direction B. The position detection-specific magnet 6 extends in the third direction C.

[0025] The position detection-specific magnet 6 includes a magnetic field generation surface 6a where the magnetic field is generated. In the present embodiment, the magnetic field generation surface 6a of the position detection-specific magnet 6 faces the position detection unit 7 and extends in the third direction C. The magnetic field generation surface 6a is a flat surface orthogonal to the second directions B. The magnetic field generation surface 4d of the rotor magnet 4c and the magnetic field generation surface 6a of the position detection-specific magnet 6 are orthogonal to each other.

[0026] The position detection unit 7 is installed on the conveying path 2 and detects the magnetic field generated by the position detection-specific magnet 6. The position detection unit 7 is arranged between the stator 3 and the position detection-specific magnet 6 in the second direction B. The position detection unit 7 is arranged away from the stator 3 in the second direction B. The position detection unit 7 is arranged away from the rotor magnet 4c in the second direction B.

[0027] As in Fig. 4, the plurality of position detection units 7 are arranged at intervals in the first direction A. The position detection units 7 shown in the drawing are two in number; however, this example is not intended to limit the number of position detection units 7. Each position detection unit 7 includes a substrate 7a and a plurality of magnetic sensors 7b mounted on the substrate 7a. The magnetic sensors 7b are, for example, magnetoresistive elements or Hall elements. The plurality of magnetic sensors 7b are arranged at intervals in the first direction A. Each magnetic sensor 7b is mounted on a surface of the substrate 7a facing the position detection-specific magnet 6. As shown in Fig. 2, the positions of the position detection-specific magnet 6 and the magnetic sensor 7b are aligned in the third direction C. The magnetic sensor 7b faces the position detection-specific magnet 6 in the second direction B. The magnetic sensor 7b is arranged away from the position detection-specific magnet 6 in the second direction B.

[0028] As in Fig. 4, the magnetic shielding elements 8 are divided in the first direction A. The magnetic shielding elements 8 shown in the drawing are two in number; however, this example is not intended to limit the number of magnetic shielding elements 8. The plurality of magnetic shielding elements 8 are arranged and installed in the first direction A with a gap 10, which provides shielding against a magnetic flux passing from the rotor magnets 4c of the rotor 4 and the coils 3b of the stator 3 to the position detection unit(s) 7. A material of the magnetic shielding elements 8 is, for example, a magnetic material. Examples of the magnetic material include a cold-rolled steel plate, a carbon steel plate, for example, S45C, and an electrical steel plate. Each magnetic shielding element 8 extends in the first direction A.In the present embodiment, each magnetic shielding member 8 is a plate-shaped member which is longer in the first direction A than in the second direction B. The magnetic shielding members 8 are arranged between the rotor magnets 4c and the position detection units 7 in the second direction B, and are arranged between the stators 3 and the position detection units 7 in the second direction B.

[0029] In the example shown, a boundary position 12 of the adjacent stators 3 in the first direction A and a boundary position 13 of the adjacent magnetic shielding elements 8 are aligned in the first direction A, but may not be aligned. To distinguish the adjacent magnetic shielding elements 8 in the following description, one magnetic shielding element 8 is referred to as the magnetic shielding element 8A, and the other magnetic shielding element 8 is referred to as the magnetic shielding element 8B.

[0030] Preferably, the plurality of magnetic shielding members 8 are arranged and installed without gaps in the first direction A. However, in practice, when the plurality of stators 3 are arranged and installed in the first direction A without gaps, the gap 10 occurs between the adjacent magnetic shielding members 8 due to unavoidable size and assembly tolerances and a gap intentionally provided to avoid problems caused by interference, etc. This gap 10 varies in size, ranging from large to small, without being noticeable at first glance. For the purpose of explanation, the gap 10 is shown larger here. The same applies to the following.

[0031] The gap-specific magnetic shielding member 9 is a member that closes the gap 10 between the adjacent magnetic shielding members 8 to provide shielding against the magnetic flux flowing from the rotor magnets 4c and the coils 3b to the position detection unit(s) 7. Specifically, the gap-specific magnetic shielding member 9 is the member that provides shielding against the magnetic flux flowing from the rotor magnets 4c and the coils 3b through the gap 10 to the position detection unit(s) 7. A material of the gap-specific magnetic shielding member 9 is, for example, a magnetic material. Examples of the magnetic material include a cold-rolled steel plate, a carbon steel plate such as S45C, and an electrical steel plate.In the present embodiment, the gap-specific magnetic shielding member 9 is formed separately from the magnetic shielding members 8. The gap-specific magnetic shielding member 9 extends in the first direction A. The gap-specific magnetic shielding member 9 is the plate-shaped member which is longer in the first direction A than in the second direction B.

[0032] The gap-specific magnetic shielding element 9 spans the gap 10 and is in contact with the two adjacent magnetic shielding elements 8. For example, the gap-specific magnetic shielding element 9 is screwed to the magnetic shielding elements 8. The magnetic shielding elements 8 and the gap-specific magnetic shielding element 9 can have the same thickness or different thicknesses. The material of the magnetic shielding elements 8 and the material of the gap-specific magnetic shielding element 9 can be the same or different.

[0033] With reference to Fig. 2, a detailed description is given of how the magnetic shielding elements 8, the rotor magnets 4c, the stators 3, and the position detection units 7 are arranged. A distance D1 is defined as the distance between the magnetic shielding element 8 and the rotor magnet 4c along the second direction B. Specifically, the distance D1 is the distance from a side of the rotor magnet 4c closer to the magnetic shielding element 8 in the second direction B to the magnetic shielding element 8. A distance D2 is defined as the distance between the magnetic shielding element 8 and the stator 3 along the second direction B. Specifically, the distance D2 is the distance from a side of the stator 3 closer to the magnetic shielding element 8 in the second direction B to the magnetic shielding element 8. A distance D3 is defined as the distance between the magnetic shielding element 8 and the position detection unit 7 along the second direction B.Specifically, the distance D3 is the distance between the magnetic shielding member 8 and the magnetic sensor 7b of the position detection unit 7 along the second direction B. In the present embodiment, the magnetic shielding members 8, the rotor magnets 4c, the stators 3, and the position detection units 7 are arranged so that both a condition that the distance D1 is shorter than the distance D3 and a condition that the distance D2 is shorter than the distance D3 are satisfied. The magnetic shielding members 8, the rotor magnets 4c, the stators 3, and the position detection units 7 can be arranged so that the condition that the distance D1 is shorter than the distance D3 and / or the condition that the distance D2 is shorter than the distance D3 are satisfied.

[0034] Next, a description will be given of effects of the linear conveyance system 1 according to the present embodiment.

[0035] As in Fig. As shown in Fig. 4, the linear conveying system 1 of the present embodiment includes the gap-specific magnetic shielding member 9, which closes the gap 10 between the adjacent magnetic shielding members 8 and is configured to provide shielding against the magnetic flux passing from the rotor magnets 4c and the coils 3b to the position detection unit(s) 7. This configuration can prevent the magnetic flux generated by the rotor magnets 4c and the coils 3b from passing through the gap 10 to the position detection unit(s) 7. As a result, this configuration can prevent the magnetic flux generated by the rotor magnets 4c and the coils 3b from interfering with the position detection unit(s) 7 through the gap 10, and therefore enables improved position detection accuracy of each rotor 4 compared to a conventional configuration.

[0036] Fig. 5 is an explanatory diagram showing an action of the linear conveying system 1 according to the first embodiment. In Fig. 5, solid arrows indicate a magnetic flux generated by the rotor magnet 4c and the coil 3b. In Fig. 5, the gap-specific magnetic shielding element 9 is not shown for the purpose of explanation. In the present embodiment, as shown in Fig. 5, the stator 3 is arranged away from the position detection-specific magnet 6 in the second direction B, and the position detection unit 7 is arranged between the stator 3 and the position detection-specific magnet 6 in the second direction B. Further, in the present embodiment, the magnetic shielding member 8 is arranged in the second direction B between the stator 3 and the position detection unit 7. These configurations allow the magnetic flux generated by the coil 3b and the rotor magnet 4c to be returned to the stator core 3a through the magnetic shielding member 8.

[0037] Specifically, a magnetic flux generated by the coil 3b when the coil 3b is energized flows through the rotor magnet 4c and then to the base 4b. When the coil 3b is energized, a magnetic flux generated by the rotor magnet 4c also flows into the base 4b. Further, a resulting magnetic flux flowing into the base 4b splits into one that takes a path toward the magnetic shielding member 8 and another that takes a path away from the magnetic shielding member 8 in the second direction B. The magnetic flux flowing from the base 4b to the magnetic shielding member 8 flows along the magnetic shielding member 8 and returns to the stator core 3a from an end of the stator core 3a directed in a direction away from the rotor 4.The magnetic flux flowing from the base 4b away from the magnetic shielding member 8 in the second direction B travels around the stator 3 and then returns to the stator core 3a from the end of the stator core 3a facing away from the rotor 4. This further reduces the interference of the position detection unit(s) 7 by the magnetic flux generated by the rotor magnets 4c and the coils 3b, thus enabling a further improvement in the position detection accuracy of each rotor 4.

[0038] As in Fig. 2, in the present embodiment, the rotor magnet 4c is arranged away from the position detection unit 7 in the second direction B, and the stator 3 is arranged away from the position detection unit 7 in the second direction B. Further, in the present embodiment, the magnetic shielding member 8 is arranged between the rotor magnet 4c and the position detection unit 7 in the second direction B, and is arranged between the stator 3 and the position detection unit 7 in the second direction B. Further, in the present embodiment, the magnetic shielding members 8, the rotor magnets 4c, the stators 3, and the position detection units 7 are arranged so that both the condition that the distance D1 is shorter than the distance D3 and the condition that the distance D2 is shorter than the distance D3 are satisfied.These configurations can further improve the effect of returning the magnetic flux generated by the coil 3b and the rotor magnet 4c to the stator core 3a through the magnetic shielding member 8. This further reduces the interference of the position detection unit(s) 7 by the magnetic flux generated by the rotor magnets 4c and the coils 3b, thus enabling a further improvement in the accuracy of position detection of each rotor 4.

[0039] As in Fig. As shown in Figure 2, in the present embodiment, the magnetic field generating surface 4d of the rotor magnet 4c and the magnetic field generating surface 6a of the position detection-specific magnet 6 are orthogonal to each other. This configuration makes it less likely that the magnetic flux generated by the rotor magnet 4c will interfere with the position detection unit 7, thus enabling a further improvement in the accuracy of position detection of the rotor 4. Second embodiment.

[0040] Next, with reference to Fig. 6, a description is given of a linear conveying system 1A according to a second embodiment. Fig. 6 is a side view showing the linear conveying system 1A according to the second embodiment. In the present embodiment, the gap-specific magnetic shielding member 9 is configured differently from that of the above-described first embodiment. The second embodiment overlaps with the above-described first embodiment, and these overlapping parts have the same reference numerals and will not be described.

[0041] Preferably, the positions of the adjacent magnetic shielding elements 8 are aligned in the second direction B. In practice, however, due to dimensional and assembly tolerances of the magnetic shielding elements 8 and their deliberate displacement, which is intended to avoid problems caused by interference of the magnetic shielding elements 8, etc., a level difference 11 may occur between the adjacent magnetic shielding elements 8. This level difference 11 varies in size, ranging from significant to minor, which is not noticeable at first glance. For the purpose of explanation, the level difference 11 is shown larger here. The positions of the adjacent magnetic shielding elements 8 in the second direction B are not aligned.In the present embodiment, the magnetic shielding member 8A is arranged closer to the stators 3 than the other magnetic shielding member 8B. The level difference 11 occurs between the adjacent magnetic shielding members 8A and 8B, which are offset in the second direction B. The gap-specific magnetic shielding member 9 is bent along the level difference 11 and is in contact with the adjacent magnetic shielding members 8A and 8B.

[0042] Next, a description will be given of an action of the linear conveyance system 1A according to the present embodiment.

[0043] In the present embodiment, the level difference 11 is formed between the adjacent magnetic shielding members 8A and 8B, which are offset in the second direction B, and the gap-specific magnetic shielding member 9 is bent along the level difference 11 and in contact with the adjacent magnetic shielding members 8A and 8B. This configuration can eliminate a magnetic gap between the magnetic shielding members 8A and 8B and the gap-specific magnetic shielding member 9 even when the level difference 11 occurs between the adjacent magnetic shielding members 8A and 8B.In other words, because the gap-specific magnetic shielding member 9 is appropriately bent along the level difference 11 between the adjacent magnetic shielding members 8A and 8B and is in contact with the adjacent magnetic shielding members 8A and 8B, the magnetic gap between the magnetic shielding members 8A and 8B and the gap-specific magnetic shielding member 9 can be eliminated. This prevents a magnetic flux generated by the rotor magnets 4c and the coils 3b from interfering with the position detection unit(s) 7, and enables improved position detection accuracy of each rotor 4 compared to a conventional configuration, even when the level difference 11 occurs between the adjacent magnetic shielding members 8A and 8B. Third embodiment.

[0044] Next, with reference to Fig. 7, a description is given of a linear conveying system 1B according to a third embodiment. Fig. 7 is a side view showing the linear conveying system 1B according to the third embodiment. In the present embodiment, the gap-specific magnetic shielding member 9 is configured differently from that of the above-described first embodiment. The third embodiment overlaps with the above-described first embodiment, and these overlapping parts have the same reference numerals and will not be described.

[0045] The gap-specific magnetic shielding member 9 is integrally formed with one of the adjacent magnetic shielding members 8. The gap-specific magnetic shielding member 9 extends from an end of the magnetic shielding member 8A facing the other magnetic shielding member 8B toward the stator 3 and then extends toward the other magnetic shielding member 8B. The gap 10 is closed by the gap-specific magnetic shielding member 9 on a side closer to the stators 3. The gap-specific magnetic shielding member 9 is in contact with a surface of the other magnetic shielding member 8B facing the stator 3.

[0046] The gap-specific magnetic shielding member 9 may extend from the end of the magnetic shielding member 8A facing the other magnetic shielding member 8B toward the position detection unit 7 and then extend toward the other magnetic shielding member 8B. In such a configuration, the gap 10 is closed by the gap-specific magnetic shielding member 9 on a side closer to the position detection units 7, and the gap-specific magnetic shielding member 9 is in contact with a surface of the other magnetic shielding member 8B facing the position detection unit 7. The gap-specific magnetic shielding member 9 may be formed on the other magnetic shielding member 8B.

[0047] Next, a description will be given of the effects of the linear conveyance system 1B according to the present embodiment.

[0048] In the present embodiment, the gap-specific magnetic shielding member 9 is integrally formed with one of the adjacent magnetic shielding members 8. This configuration enables a reduced number of components and, as in the first embodiment described above, improved position detection accuracy of each rotor 4 compared to the conventional configuration. Fourth embodiment.

[0049] Next, with reference to Fig. 8, a description is given of a linear conveying system 1C according to a fourth embodiment. Fig. 8 is a side view showing the linear conveyance system 1C according to the fourth embodiment. In the present embodiment, the gap-specific magnetic shielding member 9 is configured differently from that of the above-described first embodiment. The fourth embodiment overlaps with the above-described first embodiment, and these overlapping parts have the same reference numerals and will not be described.

[0050] The gap-specific magnetic shielding member 9 includes a first shielding part 9a extending from one of the magnetic shielding members 8 toward the other magnetic shielding member 8, and a second shielding part 9b formed on the other magnetic shielding member 8 and in contact with the first shielding part 9a. The first shielding part 9a extends from an end of the magnetic shielding member 8A facing the other magnetic shielding member 8B toward the magnetic shielding member 8B. In the present embodiment, the first shielding part 9a is a protruding part.

[0051] The second shielding part 9b is formed at an end of the magnetic shielding member 8B facing the magnetic shielding member 8A. In the present embodiment, the second shielding part 9b is a recessed part into which the first shielding part 9a is inserted. The recessed part is open toward the magnetic shielding member 8A. The recessed part is recessed in a direction away from the magnetic shielding member 8A. The recessed part, which serves as the second shielding part 9b, is in contact with the protruding part, which serves as the first shielding part 9a, on an inner surface. The gap 10 is closed by inserting the first shielding part 9a into the second shielding part 9b.

[0052] The first shielding part 9a may be the recessed part, while the second shielding part 9b is the protruding part which is inserted into the recessed part.

[0053] Next, a description will be given of the effects of the linear conveyance system 1C according to the present embodiment.

[0054] In the present embodiment, the gap-specific magnetic shielding member 9 is integrally formed with both of the adjacent magnetic shielding members 8. This configuration enables a reduced number of components and, as in the first embodiment described above, improved position detection accuracy of each rotor 4 compared to the conventional configuration.

[0055] In the present embodiment, the gap-specific magnetic shielding member 9 includes the first shielding part 9a extending from one of the adjacent magnetic shielding members 8 toward the other magnetic shielding member 8, and the second shielding part 9b formed on the other magnetic shielding member 8 and in contact with the first shielding part 9a. Specifically, the first shielding part 9a is the protruding part extending from the magnetic shielding member 8A toward the magnetic shielding member 8B. The second shielding part 9b is the depressed part formed on the magnetic shielding member 8B, and the protruding part serving as the first shielding part 9a is inserted into the second shielding part 9b. This configuration can eliminate or reduce the gap 10 between the adjacent magnetic shielding members 8A and 8B. Fifth embodiment.

[0056] Next, with reference to Fig. 9, a description is given of a linear conveying system 1D according to a fifth embodiment. Fig. 9 is a side view showing the linear conveying system 1D according to the fifth embodiment. In the present embodiment, the gap-specific magnetic shielding member 9 is configured differently from that of the above-described first embodiment. The fifth embodiment overlaps with the above-described first embodiment, and these overlapping parts have the same reference numerals and will not be described.

[0057] The gap-specific magnetic shielding member 9 includes a first shielding part 9a extending from one of the adjacent magnetic shielding members 8 toward the other magnetic shielding member 8, and a second shielding part 9b formed on the other magnetic shielding member 8 and in contact with the first shielding part 9a. The first shielding part 9a extends from an end of the magnetic shielding member 8A facing the other magnetic shielding member 8B toward the magnetic shielding member 8B. In the present embodiment, the first shielding part 9a is a protruding part. The first shielding part 9a extends from a lower half of the end of the magnetic shielding member 8A facing the other magnetic shielding member 8B toward the magnetic shielding member 8B.

[0058] The second shielding part 9b is formed at an end of the magnetic shielding member 8B facing the magnetic shielding member 8A. In the present embodiment, the second shielding part 9b is a protruding part. The second shielding part 9b extends from an upper half of the end of the magnetic shielding member 8B facing the magnetic shielding member 8A toward the magnetic shielding member 8A. The positions of the first and second shielding parts 9a and 9b in the first direction A are aligned. The first and second shielding parts 9a and 9b overlap each other in the second direction B. In other words, the first and second shielding members 9a and 9b are arranged to overlap each other when viewed in the second direction B. The second shielding part 9b is in contact with a surface of the first shielding part 9a facing the stators 3.

[0059] In the present embodiment, the second shielding member 9b may be in contact with a surface of the first shielding member 9a facing the positioning detection units 7.

[0060] Next, a description will be given of the effects of the linear conveyance system 1D according to the present embodiment.

[0061] In the present embodiment, the gap-specific magnetic shielding member 9 is formed integrally with both of the adjacent magnetic shielding members 8. This configuration enables a reduced number of components and, as in the first embodiment described above, improved position detection accuracy of each rotor 4 compared to the conventional configuration.

[0062] In the present embodiment, the gap-specific magnetic shielding member 9 includes the first shielding part 9a extending from one of the adjacent magnetic shielding members 8 toward the other magnetic shielding member 8, and the second shielding part 9b formed on the other magnetic shielding member 8 and in contact with the first shielding part 9a. Specifically, the first shielding part 9a is the protruding part extending from the magnetic shielding member 8A toward the magnetic shielding member 8B. The second shielding part 9b is the protruding part extending from the magnetic shielding member 8B toward the magnetic shielding member 8A and is arranged to overlap the first shielding part 9a as viewed in the second direction B.This configuration can eliminate or reduce the gap 10 between the adjacent magnetic shielding elements 8A and 8B. Sixth embodiment.

[0063] Next, with reference to Fig. 10, a description is given of a linear conveying system 1E according to a sixth embodiment. Fig. 10 is a side view showing the linear conveying system 1E according to the sixth embodiment. In the present embodiment, the gap-specific magnetic shielding member 9 is configured differently from that of the above-described first embodiment. The sixth embodiment overlaps with the above-described first embodiment, and these overlapping parts have the same reference numerals and will not be described.

[0064] The gap-specific magnetic shielding member 9 includes a first shielding part 9a extending from one of the adjacent magnetic shielding members 8 toward the other magnetic shielding member 8, and a second shielding part 9b formed on the other magnetic shielding member 8 and in contact with the first shielding part 9a.

[0065] The first shielding part 9a extends from an end of the magnetic shielding element 8A facing the other magnetic shielding element 8B in the direction of the magnetic shielding element 8B. The further the first shielding part 9a extends from the magnetic shielding element 8A to the magnetic shielding element 8B, the closer the first shielding part 9a is curved to the stator 3. The first shielding part 9a comprises a first bent part 9c and a first contact part 9d. The first bent part 9c is a curved part formed between the first contact part 9d and the end of the magnetic shielding element 8A facing the other magnetic shielding element 8B. The further the first contact part 9d extends from the first bent part 9c to the magnetic shielding element 8B, the closer the first contact part 9d extends in a curved shape to the stator 3.The first contact part 9d is elastically deformable around the first bent part 9c in the first direction A.

[0066] The second shielding part 9b extends from an end of the magnetic shielding element 8B facing the magnetic shielding element 8A in the direction of the magnetic shielding element 8A. The further the second shielding part 9b extends from the magnetic shielding element 8B to the magnetic shielding element 8A, the closer the second shielding part 9b is curved to the stator 3. The first shielding part 9a and the second shielding part 9b have a symmetrical shape in the first direction A. The second shielding part 9b comprises a second bent part 9e and a second contact part 9f. The second bent part 9e is a curved part which is located between the second contact part 9f and the end of the magnetic shielding element 8B facing the magnetic shielding element 8A.The further the second contact part 9f extends from the second bent part 9e to the magnetic shielding element 8A, the closer the second contact part 9f extends to the stator 3 in a curved shape. The second contact part 9f is elastically deformable around the second bent part 9e in the first direction A.

[0067] When a front end of the first contact part 9d comes into contact with a front end of the second contact part 9f during assembly of the magnetic shielding members 8 integrally formed with the gap-specific magnetic shielding member 9, the first contact part 9d is elastically deformed in a direction away from the second contact part 9f around a boundary part between the first contact part 9d and the first bent part 9c and then pressed against the second contact part 9f under the action of the elastic restoring force of the boundary part.On the other hand, when the front end of the second contact part 9f comes into contact with the front end of the first contact part 9d during assembly of the magnetic shielding elements 8 integrally formed with the gap-specific magnetic shielding element 9, the second contact part 9f is elastically deformed in a direction away from the first contact part 9d around a boundary portion between the second contact part 9f and the second bent part 9e, and then pressed against the first contact part 9d under the action of the elastic restoring force of the boundary portion. The first and second shielding parts 9a and 9b press each other in their contact relationship, thereby closing the gap 10.

[0068] The further the first shielding part 9a extends toward the magnetic shielding element 8B, the closer the first shielding part 9a can be curved to the position detection unit 7. The further the second shielding part 9b extends toward the magnetic shielding element 8A, the closer the second shielding part 9b can be curved to the position detection unit 7.

[0069] Next, a description will be given of the effects of the linear conveyance system 1E according to the present embodiment.

[0070] In the present embodiment, the gap-specific magnetic shielding member 9 is formed integrally with both of the adjacent magnetic shielding members 8. This configuration enables a reduced number of components and, as in the first embodiment described above, improved position detection accuracy of each rotor 4 compared to the conventional configuration.

[0071] In the present embodiment, the gap-specific magnetic shielding member 9 includes the first shielding part 9a extending from one of the adjacent magnetic shielding members 8 toward the other magnetic shielding member 8, and the second shielding part 9b formed on the other magnetic shielding member 8 and in contact with the first shielding part 9a. Specifically, the first and second shielding members 9a and 9b have the elastic restoring force that urges them into contact. This configuration can eliminate or reduce the gap 10 between the adjacent magnetic shielding members 8A and 8B.

[0072] In addition, since the first and second shielding members 9a and 9b in the present embodiment have the elastic restoring force, they press each other into contact. Even if the Fig.Therefore, when the level difference 11 shown in FIG. 6 exists between the adjacent magnetic shielding elements 8A and 8B, the first and second shielding parts 9a and 9b will be in contact with each other in elastic deformation appropriate for the level difference 11. Accordingly, a magnetic gap between the first shielding part 9a and the second shielding part 9b can be eliminated. This prevents the magnetic flux generated by the rotor magnets 4c and the coils 3b from interfering with the position detection unit(s) 7 even when the level difference 11 occurs between the adjacent magnetic shielding elements 8A and 8B, and enables improved accuracy of position detection of each rotor 4 compared to a conventional configuration.

[0073] The above configurations shown in the embodiments are exemplary, can be combined with other publicly known techniques, and can be partially omitted or modified without departing from the core idea. The embodiments can be combined with each other. List of reference symbols 1, 1A, 1B, 1C, 1D, 1E linear conveyor system; 2 transport route; 3 Stator; 3a Stator core; 3b coil; 3c core back; 3d tooth; 4 runners; 4a housing; 4b Basis; 4c rotor magnet; 4d, 6a magnetic field generation area; 5 Position detector; 6 position detection specific magnet; 7 Position detection unit; 7a substrate; 7b magnetic sensor; 8, 8A, 8B magnetic shielding element; 9 gap-specific magnetic shielding element; 9a first shielding part; 9b second shielding part; 9c first bent part; 9d first contact part; 9e second curved part; 9f second contact part; 10 gap; 11 level difference; 12, 13 border position; A first direction; B second direction; C third direction. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2021 / 124 439

[0006]

Claims

[1] Position detector, comprising: a position detection-specific magnet installable on a rotor for moving along a conveying path comprising a stator; a position detection unit installable on the conveying path, which detects a magnetic field generated by the position detection-specific magnet; a plurality of magnetic shielding elements which are arrangeable and installable with a gap in a first direction, which is a direction of movement of the rotor along the conveying path, wherein the magnetic shielding elements are configured to provide shielding against a magnetic flux running from a rotor magnet of the rotor and coils of the stator to the position detection unit; and a gap-specific magnetic shielding element closing the gap between adjacent magnetic shielding elements of the magnetic shielding elements, wherein the gap-specific magnetic shielding element is configured to provide shielding against the magnetic flux. [2] Position detector according to claim 1, wherein there is a level difference between the adjacent magnetic shielding elements which are offset in a second direction which is a direction orthogonal to the first direction, and the gap-specific magnetic shielding element is bent along the level difference and is in contact with the adjacent magnetic shielding elements. [3] Position detector according to claim 1 or 2, wherein the position detection-specific magnet is designed to be arranged away from the stator in a second direction, which is a direction orthogonal to the first direction, the position detection unit is designed to be arranged in the second direction between the stator and the position detection-specific magnet, and the magnetic shielding elements are designed to be arranged in the second direction between the stator and the position detection unit. [4] Position detector according to one of claims 1 to 3, wherein the magnetic shielding elements are designed to be arranged between the rotor magnet and the position detection unit arranged away from the rotor magnet in a second direction, wherein the magnetic shielding elements are designed to be arranged between the stator and the position detection unit arranged away from the stator in the second direction, wherein the second direction is a direction orthogonal to the first direction, and the magnetic shielding elements, the rotor magnet, the stator and the position detection unit can be arranged such that a condition that a distance between the magnetic shielding elements and the rotor magnet along the second direction is shorter than a distance between the magnetic shielding elements and the position detection unit along the second direction, and / or a condition that a distance between the magnetic shielding elements and the stator along the second direction is shorter than a distance between the magnetic shielding elements and the position detection unit along the second direction is met. [5] A position detector according to any one of claims 1 to 4, wherein the gap-specific magnetic shielding member is integrally formed with at least one of the adjacent magnetic shielding members. [6] A position detector according to any one of claims 1 to 5, wherein the gap-specific magnetic shielding element comprises: a first shielding part extending from one of the adjacent magnetic shielding elements towards the other magnetic shielding element, and a second shielding part formed on the other magnetic shielding member, the second shielding part being in contact with the first shielding part. [7] Linear conveying system comprising: a conveyor path with a stator; a slider for moving along the conveying path, the slider forming a linear servo motor with the stator; a position detection specific magnet installed on the rotor; a position detection unit installed on the conveying path, which detects a magnetic field generated by the position detection-specific magnet; a plurality of magnetic shielding elements arranged and installed with a gap in a first direction, which is a direction of movement of the rotor along the conveying path, wherein the plurality of magnetic shielding elements are configured to provide shielding against a magnetic flux passing from a rotor magnet of the rotor and coils of the stator to the position detection unit; and a gap-specific magnetic shielding element closing the gap between adjacent magnetic shielding elements of the magnetic shielding elements, wherein the gap-specific magnetic shielding element is configured to provide shielding against the magnetic flux. [8] Linear conveying system according to claim 7, wherein there is a level difference between the adjacent magnetic shielding elements which are offset in a second direction which is a direction orthogonal to the first direction, and the gap-specific magnetic shielding element is bent along the level difference and is in contact with the adjacent magnetic shielding elements. [9] Linear conveying system according to claim 7 or 8, wherein the position detection-specific magnet is arranged away from the stator in a second direction, which is a direction orthogonal to the first direction, the position detection unit is arranged in the second direction between the stator and the position detection-specific magnet, and the magnetic shielding elements are arranged in the second direction between the stator and the position detection unit. [10] Linear conveying system according to one of claims 7 to 9, wherein the position detection unit is arranged away from the rotor magnet in a second direction, which is a direction orthogonal to the first direction, the position detection unit is arranged away from the stator in the second direction, the magnetic shielding elements are arranged in a second direction between the rotor magnet and the position detection unit and are arranged in the second direction between the stator and the position detection unit, and the magnetic shielding elements, the rotor magnet, the stator and the position detection unit are arranged such that a condition that a distance between the magnetic shielding elements and the rotor magnet along the second direction is shorter than a distance between the magnetic shielding elements and the position detection unit along the second direction, and / or a condition that a distance between the magnetic shielding elements and the stator along the second direction is shorter than a distance between the magnetic shielding elements and the position detection unit along the second direction is met. [11] The linear conveying system according to any one of claims 7 to 10, wherein a magnetic field generating surface of the rotor magnet and a magnetic field generating surface of the position detection specific magnet are orthogonal to each other. [12] A linear conveying system according to any one of claims 7 to 11, wherein the gap-specific magnetic shielding member is integrally formed with at least one of the adjacent magnetic shielding members. [13] A linear conveying system according to any one of claims 7 to 12, wherein the gap-specific magnetic shielding element comprises: a first shielding part extending from one of the adjacent magnetic shielding elements towards the other magnetic shielding element, and a second shielding part formed on the other magnetic shielding member, the second shielding part being in contact with the first shielding part.

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