JP2007071612A - Rotation angle detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation angle detection device applied to detection of a rotation angle of a joint part of a machine with a joint or a turning shaft of a machine with the turning shaft, having a small size, high resolution and high resistance against an environmental change, capable of detecting an absolute angle, and improving assembleability and incorporability. <P>SOLUTION: In this rotation angle detection device, the rotation angle of a joint part is detected, in a machine with the joint such as a construction machine or an industrial machine having the joint part. A magnetism generation means 28 having circumferential direction anisotropy around the rotation center is provided on either joint constituting member between a pair of mutually-rotatable joint constituting members constituting the joint part. A magnetic array sensor 29 for detecting magnetism from the magnetism generation means 28 is provided on the other joint constituting member oppositely to the axial direction of the rotation center of the magnetism generation means 28. An angle calculation means 30 for calculating the rotation angle of the magnetism generation means 28 from an output from the magnetic array sensor 29 is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rotation angle detection device that detects a rotation angle of a joint part in a jointed machine such as a construction machine or an industrial machine, or a rotation angle of a swivel axis in a machine with a swivel axis such as a construction machine having a swivel axis.

  In order to detect the rotation angle of joints and swiveling axes of construction machinery, industrial machinery, robots, etc., contact type potentiometers and magnetic rotation sensors such as MR sensors and hall sensors are used for joints and swiveling shafts. Often installed.

As a rotation angle detection device that can be incorporated in a small device and can detect rotation with high accuracy, a combination of a magnetic generation means and a magnetic line sensor has been proposed (Patent Document 2). This discloses that it is used for rotation detection for rotation control of a small motor and rotation detection for position detection of office equipment. Further, it is disclosed that a bearing and a rotation detection unit are integrated to form a bearing with a rotation detection device.
JP-A-9-105604 JP 2004-037133 A

However, the contact type potentiometer has the following problems.
(1) Since the contact type wears, there is a problem in durability, and further assembly adjustment such as contact pressure management of the contact is necessary.
(2) The contact type requires conversion from the resistance value (voltage value) of the resistor to the rotation angle, and correction of non-linearity is also required to increase detection accuracy.

In addition, the magnetic rotation sensor has the following problems.
(1) In the magnetic method, since the absolute angle cannot be detected in the pulse output method, it is necessary to separately provide a means for detecting the origin of the absolute angle, and to perform the origin finding operation before the operation.
(2) In the magnetic type, it is necessary to strictly manage the sensor gap in order to increase the resolution, and the assembly adjustment work becomes complicated.
(3) The magnetic pattern detected by the magnetic sensor must be made fine, and it is difficult to reduce the diameter and size.
(4) When the absolute angle is detected by a magnetic method, a means for correcting the nonlinearity of the sensor is necessary to ensure the detection accuracy, and correction of the temperature characteristic is also required.

  The magnetic line sensor type rotation angle detection device disclosed in Patent Document 2 has various excellent functions, but as an application example, for rotation detection for rotation control of a small motor and position detection of office equipment. Only rotation detection is disclosed, and an application example to a joint part, a turning shaft, or the like is not disclosed.

  The object of the present invention is applied to the detection of the rotation angle of a joint part in a machine with a joint and the turning axis in a machine with a turning shaft, and can detect an absolute angle with a small size and high resolution, and is also resistant to environmental changes. Another object of the present invention is to provide a rotation angle detection device capable of improving the assembling property and the assembling property.

A rotation angle detection device according to a first aspect of the present invention is a device for detecting a rotation angle of a joint part in a jointed machine such as a construction machine or an industrial machine having a joint part, and constitutes the joint part. A magnetic generating means provided on one of the pair of joint constituent members that are rotatable with respect to each other or a member integrated with the joint constituent member and having circumferential anisotropy around the center of rotation; A magnetic array sensor for detecting the magnetism of the magnetic generating means provided on the other joint constituent member or a member integrated with the joint constituent member facing the axial direction of the rotation center of the magnetic generating means; An angle calculating means for calculating the rotation angle of the magnetism generating means from the output of the magnetic array sensor is provided.
According to the combination of the magnetic array sensor and magnetism generating means, the rotation angle can be detected by measuring the magnetic field distribution. Therefore, unlike the detection by the strength of the magnetic field, the rotation angle can be detected with a small size and high resolution with absolute angle detection. It becomes a detection device. Therefore, when the rotation angle detection device having the above configuration is mounted on the joint portion of the jointed machine, the absolute rotation angle of the joint portion can be detected with high resolution in a small space. In addition, since this rotation angle detection device uses the principle based on the magnetic field distribution measurement, it is not affected by the temperature characteristics of the magnetism generating means, and has a characteristic that it is resistant to environmental changes. Thereby, the precision of attachment adjustment becomes unnecessary and the assembly work can be simplified. As a result, it is compact, resistant to environmental changes, and can improve assemblability and incorporation.

In this invention, a pair of mutually rotatable joint constituent members constituting the joint portion are connected to each other through a bearing so that the bearing has the magnetism generating means and the magnetic array sensor. A bearing with a rotation detector provided with an angle detector may be used.
By integrating the rotation angle detection device into the bearing in this way, the mounting adjustment can be simplified, and the number of parts and assembly man-hours of an articulated machine that is a bearing-using device can be reduced, and further downsizing can be achieved.

According to a second aspect of the present invention, there is provided a rotation angle detection device for detecting a rotation angle of the turning shaft in a machine with a turning shaft such as a construction machine having a turning shaft, the turning shaft or the turning shaft. And a magnetism generating means provided in a member that revolves integrally with the head and having a circumferential anisotropy around the swivel center, and a non-turning side member facing the axial direction of the swivel center of the magnetism generating means. It is characterized by comprising a magnetic array sensor for detecting the magnetism of the magnetic generation means and an angle calculation means for calculating the rotation angle of the magnetic generation means from the output of the magnetic array sensor.
Also in this configuration, the combination of the magnetic array sensor and the magnetism generating means can exhibit the advantage that absolute angle detection is possible with a small size and high resolution. In particular, when applied to a swivel axis, the magnetic array sensor eliminates the need to use the outer peripheral surface of the swivel axis for detecting the rotation angle, so the advantage of downsizing becomes more effective, and the absolute rotation axis The rotation angle can be detected with high resolution. As a result, high resolution and compactness of the apparatus can be realized. In addition, it is resistant to environmental changes and can improve assemblability and incorporation.

In this invention, the swivel shaft is supported so as to be able to swivel through a bearing, and the bearing is a bearing with a rotation detecting device provided with an angle detector having the magnetism generating means and a magnetic array sensor. May be.
In this configuration as well, the rotation angle detector can be integrated into the bearing to simplify installation adjustment, reduce the number of parts and assembly man-hours for the machine with a pivot shaft that is a bearing-using device, and make it even more compact Can be achieved.

According to a third aspect of the present invention, there is provided a rotation angle detection device connector including a plurality of rotation angle detection devices according to any one of the above inventions, and data transmission means for transmitting and receiving signals between the plurality of rotation angle detection devices. It is provided.
When the data transmission means is provided in this way, even if the device provided with the rotation angle detection device has a configuration like a series articulated robot, the rotation angle detection devices can be connected with one system of wiring. Therefore, the rotation angle detection device can be configured in a compact manner, and the number of connection cables can be reduced, thereby reducing connection errors in wiring work. In addition, the degree of freedom in designing an apparatus such as a serial articulated robot is increased.

  A rotation angle detection device according to a first aspect of the present invention is a device for detecting a rotation angle of a joint part in a jointed machine such as a construction machine or an industrial machine having a joint part, and constitutes the joint part. A magnetic generating means provided on one of the pair of joint constituent members that are rotatable with respect to each other or a member integrated with the joint constituent member and having circumferential anisotropy around the center of rotation; A magnetic array sensor for detecting the magnetism of the magnetic generating means provided on the other joint constituent member or a member integrated with the joint constituent member facing the axial direction of the rotation center of the magnetic generating means; Since it is equipped with an angle calculation means for calculating the rotation angle of the magnetism generation means from the output of the magnetic array sensor, it is applied to the detection of the rotation angle of the joint part in an articulated machine. , Capable of high-resolution absolute angle detected by the space-saving, it can be resistant to environmental changes, improving the assembling property and embedded resistance.

  According to a second aspect of the present invention, there is provided a rotation angle detection device for detecting a rotation angle of the turning shaft in a machine with a turning shaft such as a construction machine having a turning shaft, the turning shaft or the turning shaft. And a magnetism generating means provided in a member that revolves integrally with the head and having a circumferential anisotropy around the swivel center, and a non-turning side member facing the axial direction of the swivel center of the magnetism generating means. Since the magnetic array sensor for detecting the magnetism of the magnetism generation means and the angle calculation means for calculating the rotation angle of the magnetism generation means from the output of the magnetic array sensor are provided, the rotation angle of the swivel axis in the machine with the swivel axis It can be applied to the detection of space and can detect absolute angles with high resolution and space, is resistant to environmental changes, and can improve assembly and incorporation.

  According to a third aspect of the present invention, there is provided a rotational angle detection device assembly including a plurality of rotation angle detection devices having any one of the above configurations of the present invention, and data for transmitting and receiving signals between the plurality of rotation angle detection devices. Since a transmission means is provided, it is possible to take out a large number of sensor signals with a small number of wires, and when applied to an articulated robot or the like, the rotation angle detection device can be configured compactly, and the wiring can be saved. This makes it possible to increase the degree of freedom in designing robots and the like.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cable connection diagram of an articulated robot that is an articulated machine to which the rotation angle detection device of this embodiment is applied and a control device thereof. The articulated robot 1 is a series articulated robot in which a plurality of arm portions 3 are connected in series at joint portions 2 and the arm portions 3 are rotatable with respect to each other at the joint portions 2. 4 are each supported by the bearing 5 with a rotation detection apparatus. That is, each joint portion 2 is composed of a pair of mutually rotatable arm portions 3 and 3 which are joint constituent members, and the shaft 4 is provided at one end of one arm portion 3 of the both arm portions 3. One end of the other arm portion 3 is rotatably connected to the shaft 4 via the bearing 5 with the rotation detecting device. The rotation angle detection devices 6A to 6D (FIG. 2) of each bearing 5 and the control device 20 for controlling the entire articulated robot 1 are connected in a daisy chain manner via the cable 7, and each rotation angle detection device 6A. The rotation information (the number of rotations or the rotation angle) which is a detection signal output from ˜6D is transmitted to the control device 20.

  FIG. 2 is a cross-sectional view showing an example of a bearing 5 with a rotation detection device mounted on the articulated robot 1. This bearing 5 with a rotation detection device is a rolling bearing in which a rolling element 24 held by a cage 23 is interposed between rolling surfaces of an inner ring 21 and an outer ring 22. The rolling element 24 is made of a ball, and the rolling bearing 5 is a deep groove ball bearing. Further, for example, the shaft 4 serving as a rotating member is fitted to the inner ring 21 and supported by the outer ring 22 via the rolling elements 24. In two adjacent arm portions 3 in FIG. 1, the shaft 4 is provided in one arm portion 3, and the outer ring 22 is installed in the other arm portion 3.

  A magnetism generating means mounting member 26 is attached to the inner ring 21, and a magnetism generating means 28 is attached to the magnetism generating means mounting member 26. A sensor attachment member 27 is attached to the outer ring 22, and the angle detector 8 made of a semiconductor chip on which the magnetic array sensor 29 and the angle calculation means 30 of FIG. 3 are integrated is attached to the sensor attachment member 27. The cable 7 is also attached to the sensor attachment member 27. These structures and the data communication unit 9a (FIG. 5) constitute rotation detection devices 6A to 6D.

  FIG. 3 is a perspective view showing a conceptual configuration of the rotation detection devices 6A to 6D in the bearing 5 with the rotation detection device. Of the inner ring 21 and the outer ring 22 that rotate relatively in the bearing 5 of FIG. 2, the magnetic generation means 28 is provided on the inner ring 21 side (the magnetic generation means mounting member 26) and relatively rotates around the rotation center O of the shaft 4. . On the outer ring 22 side (sensor mounting member 27), there is provided an angle detector 8 made of a semiconductor chip on which a magnetic array sensor 29 and an angle calculator 30 are integrated.

  The magnetism generating means 28 is a member that generates magnetism, and is made of a single permanent magnet or a composite of a permanent magnet and a magnetic material, and has directionality around the rotation center O. In this case, the magnetism generating means 28 is integrated by sandwiching one permanent magnet 31 between two magnetic yokes 32, 32 so that the general shape is a bifurcated fork. One end of one magnetic yoke 32 is N One end of the magnetic pole and the other magnetic yoke 32 is an S magnetic pole.

The magnetic array sensor 29 is a sensor for detecting the magnetism of the magnetism generating means 28, and includes sensor rows 29A to 29D arranged along each side of four sides of a virtual rectangle as shown in FIG. The sensor rows 29A to 29D on each side are composed of magnetic line sensors in which the magnetic sensor elements 29a are arranged in one row or multiple rows. In this case, the center of the rectangle coincides with the rotation center O of the shaft 4. Each magnetic sensor element 29a is composed of, for example, a magnetic transistor element or a Hall element. The output of each magnetic sensor element 29a in the magnetic array sensor 29 is amplified and digitized by an AD conversion circuit.
The angle calculation means 30 is composed of an integrated circuit, and is integrated with a magnetic array sensor 29 on a semiconductor chip. The angle calculation means 30 can output the angle signal by calculating the rotation angle from the output signal of each magnetic sensor element 29a according to a predetermined relational expression or a predetermined relation table.
The magnetic array sensor 29 may be one in which the magnetic sensor elements 29A to 29D are arranged in a rectangular shape, and magnetic sensor elements are arranged in a matrix of a plurality of rows vertically and horizontally.

  According to the rotation angle detection devices 6A to 6D having this configuration, the angle detection processing is realized by the sensor element 29a and the angle calculation means 30 integrated in the semiconductor, so that the absolute angle can be accurately detected alone. In the detection method using the intensity of the magnetic field itself, the influence of the temperature characteristics of the magnet and the non-linear characteristics of the sensor is large, so that complicated correction processing is required. However, since the angle is detected from the distribution of the magnetic field on the magnetic array sensor 29, it is not affected by temperature, nonlinear characteristics, etc., and no correction process is required. Therefore, the configuration of the rotation angle detection devices 6A to 6D becomes simple, the number of parts is small, and high-resolution angle detection can be realized with a compact configuration. Moreover, since it is a non-contact type, there is no problem of wear.

  FIG. 5 is a block diagram showing a part of the rotational angle detection device connector 10 in the articulated robot 1. The cable 7 includes a data cable 7A and a power cable 7B. The rotation angle detection devices 6A to 6D include an angle detection unit 8 that detects a rotation angle or a rotation number, a data communication unit 9a that transmits rotation information of the angle detection unit 8 together with an identification number ID from an output terminal, and other rotations. And an input terminal capable of inputting the rotation information and the identification number ID transmitted from the angle detection device. The data communication unit 9a and the data cable 7A of each of the rotation angle detection devices 6A to 6D constitute a data transmission means 9 that transmits and receives signals between the rotation angle detection devices 6A to 6D. Specifically, the data communication unit 9a has an identification number determination function for determining the identification number ID of each of the rotation angle detection devices 6A to 6D viewed from the control device 20 according to the connection state of the plurality of rotation detection devices 6A to 6D. Have. That is, the identification number determination function performs a predetermined calculation on the identification number ID out of the rotation information and the identification number ID of the other rotation angle detection device input to the input terminal, and outputs the same together with the rotation information from the output terminal. The self identification number ID is given. Here, the self identification numbers ID assigned by the rotation angle detection devices 6A to 6D are all the same (specifically ID = 0).

  The information transmission operation in the rotational angle detection device connector 10 will be described below with reference to FIG. 5 together with FIG. In the data flow in the rotation angle detection device connector 10, the rotation angle detection device 6B is on the upstream side and the control device 20 is on the downstream side when viewed from the rotation angle detection device 6A. Further, the rotation angle detection device 6C is on the upstream side when viewed from the rotation angle detection device 6B, and the rotation angle detection device 6D is on the upstream side when viewed from the rotation angle detection device 6C. For example, an output signal from the rotation detection device 6B is input to the control device 20 via the downstream rotation detection device 6A. The control device 20 that has received the output signal from the rotation detection device 6A needs to identify which rotation angle detection device the received rotation information belongs to, and therefore performs the identification according to the following procedure.

For example, a packet (identification number ID + rotation information) transmitted from the data communication unit 9a (FIG. 5) of the rotation angle detection device 6B is received by the rotation angle detection device 6A and then transmitted to the control device 20. All the rotation angle detection devices 6A to 6D transmit, to the downstream side, packets in which their rotation information (number of rotations and angles) is assigned 0 as an identification number ID. When each of the rotation detection devices 6A to 6D receives a packet from another rotation angle detection device, it adds 1 to the identification number ID in the packet and transmits it downstream. When the error correction code depends on the identification number ID when transmitting downstream, the error correction code is also corrected.
When the control device 20 receives the packet and the identification number ID in the packet is 0, the rotation information of the packet is that of the rotation angle detection device 6A, and the identification number ID in the packet is 1 If so, the control device 20 can determine that the rotation information of the packet is that of the rotation angle detection device 6B.

That is, the above operation is summarized as follows.
(1) The unique identification number ID of each of the rotation detection devices 6A to 6D is 0, and each rotation angle detection device 6A to 6D adds a header, an error code, etc. together with the rotation information to the identification number ID. However, it is output downstream as one packet.
(2) Each rotation angle detection device 6A to 6D adds 1 to the identification number ID and transmits the packet of the rotation angle detection device obtained from the upstream to the downstream.
According to the above procedure, the identification numbers ID of the respective rotation angle detection devices 6A to 6D viewed from the control device 20 are the rotation angle detection device 6A No. 0, the rotation angle detection device 6B No. 1, and the rotation angle detection device 6C No. 2. The rotation angle detection device 6D becomes No. 3, and the control device 20 can identify the rotation angle detection devices 6A to 6D. That is, the rotation detection devices 6A to 6D and the control device 20 are connected in a daisy chain manner via the cable 7, so that the identification number ID is automatically determined when a signal is input to the control device 20. The In addition, when the rotation angle detection device is connected further upstream than the rotation angle detection device 6D, the identification number ID of the rotation angle detection device is No. 4, and the rotation viewed from the control device 20 toward the upstream side. The value of the identification number ID of the angle detection device increases.

  As described above, when the rotation angle detectors 6A to 6D are mounted on the articulated robot 1, the absolute rotation angle of the joint portion 2 can be detected with high resolution in a small space. In addition, since the rotation angle detection devices 6A to 6D use the principle based on the magnetic field distribution measurement, the rotation angle detection devices 6A to 6D are not affected by the temperature characteristics of the permanent magnet 31 (FIG. 3) that is a constituent member of the magnetism generation means 28, and the environment The characteristic of being resistant to change is obtained. Thereby, the precision of attachment adjustment becomes unnecessary and the assembly work can be simplified. In particular, in this embodiment, since the rotation detecting device bearings 5 (FIG. 2) in which the rotation angle detecting devices 6A to 6D and the bearing are integrated are mounted on the articulated robot 1, adjustment of mounting can be made unnecessary. As a result, it is compact, resistant to environmental changes, and can improve assemblability and incorporation. Further, since the rotation angle detection devices 6A to 6D are non-contact type, there is no problem of wear.

Further, according to the rotation angle detection device connection body 10 having the configuration shown in FIG. 5, since the identification numbers ID of the rotation angle detection devices 6A to 6D are all 0, they are unique to the rotation angle detection devices 6A to 6D. There is no need to set the identification number ID. Accordingly, there is no need to provide a switch for setting a unique identification number ID or a writable nonvolatile memory in the rotation angle detection devices 6A to 6D to store the identification number ID, and the rotation angle detection devices 6A to 6D are compact. In addition, the configuration of the control device 20 can be simplified because it can be configured at low cost and it is not necessary to manage the identification numbers ID so as not to overlap.
In addition, since each of the rotation angle detection devices 6A to 6D and the control device 20 are connected in a daisy chain system, even if the articulated machine has a configuration like the serial articulated robot 1, one line of wiring is provided to the tip. For this reason, the number of cables 7 is reduced, the number of input terminals of the control device 20 can be reduced, and connection errors in the wiring work of the cables 7 can be reduced. In addition, the degree of freedom in designing the articulated robot 1 is increased.

  FIG. 7 shows another embodiment of the present invention. In this embodiment, the rotation angle detection device shown in FIGS. 2 to 4 is applied to an articulated hand 15 in a humanoid robot that is a jointed machine, and the joints of the fingers 15A to 15E of the articulated hand 15 are applied. A rotation angle detection device 6 is provided for each part. In the rotation angle detection device connector 10 in this embodiment, not all the rotation angle detection devices 6 are connected by a cable 7 in a single stroke, but a daisy chain method for each rotation angle detection device 6 of each finger 15A to 15E. And the cable 7 of each finger and the control device 20 are relayed by a relay device 16 having 5 inputs and 1 output.

  In the information transmission operation of the rotation detection device connector 10 in this embodiment, the flow of data from the rotation angle detection device arranged for each finger 15A to 15E to the relay device 16 is the first shown in FIGS. This is the same as the data flow to the control device 20 in the embodiment. The data transmission means 9 includes the relay device 16, the data communication unit 9a of FIG. 5, and the data cable 7A. In the embodiment of FIG. 7, the relay device 16 adds a predetermined numerical value (including 0) different for each finger to the identification signal ID of the packet from each finger 15A to 15E input from each input terminal. To the control device 20 from one output terminal. As a result, in the packet received by the control device 20, the identification numbers ID of the rotation angle detection devices 6A1 to 6E3 are different, and the control device 20 recognizes the rotation information of the rotation angle detection devices 6A1 to 6E3. it can.

  In this embodiment in which the rotation angle detection device 6 is mounted on the multi-joint hand 15, the absolute angles of the joint portions of the fingers 15A to 15E are detected by the compact rotation angle detection device 6 and output as digitized numerical values. . Since the wiring necessary for collecting these data can be minimized, the wiring of the robot can be simplified and the reliability, assemblability and maintainability can be improved.

  FIG. 8 shows still another embodiment of the present invention. In this embodiment, the rotation angle detection device (FIG. 3) shown in the first embodiment is mounted on a jointed machine such as a robot having a joint portion 2 composed of a plurality of rotation axes intersecting each other. The joint portion 2 in this case has a rotation shaft 13 arranged vertically and a rotation shaft 14 arranged horizontally. A first joint constituent member 11 having a U-shaped cross section is provided at the upper end of the vertical rotating shaft 13, and the second joint constituent member 12 is disposed between the pair of left and right standing plates 11 a and 11 a of the joint constituent member 11. Has been. Further, the horizontal rotation shaft 14 is laid horizontally so as to span between the compatible plate portions 11a and 11a of the first joint component member 11, and the horizontal rotation shaft 14 is supported by the second joint component member 12. And is connected to the joint component 12. As a result, the second joint component member 12 can swing around the axis of the vertical rotation shaft 13 and can swing around the axis of the horizontal rotation shaft 14. The vertical rotation shaft 13 is rotatably supported by a bearing housing 17 projecting on the base 19 via a bearing, and the rotation angle detection device 6 is provided between the bearing housing 17 and the vertical rotation shaft 13.

  In this case, the magnetism generating means 28 (FIG. 3) is provided in the bearing housing 17 which is a fixed side member, and the angle detector 8 (see FIG. 3) are provided respectively. Further, the horizontal rotary shaft 14 is also rotatably supported via a bearing on a bearing housing 18 fixed to one upright plate portion 11a of the second joint component member 12, and the bearing housing 18, the horizontal rotary shaft 14, Between them, a rotation angle detection device 6 is provided.

Even when the rotation angle detection device 6 is mounted on the joint portion 2 having a structure in which the plurality of rotation shafts 13 and 14 intersect as described above, the rotation angle detection device 6 is compact and has high detection resolution. The degree of freedom in designing the joint module can be increased, and sufficient rotation angle detection capability can be ensured.
In the case where the rotary shafts 13 and 14 are driven by a motor, a reduction gear is interposed between the rotary shafts 13 and 14 and the output shaft of the motor, so the rotation angle after deceleration must be detected. It may be necessary. In this case, by using the bearing 5 with the rotation detection device (FIG. 2) in the first embodiment in which the rotation angle detection device 6 and the bearing are integrated, the rotation angle of the rotary shafts 13 and 14 can be detected. Can be easily performed.

  FIG. 9 shows still another embodiment of the present invention. In this embodiment, a construction machine having a plurality of joint portions 2 is mounted with the rotation angle detection device (FIG. 3) shown in the first embodiment. The construction machine 25 in this case is an excavator in which a plurality of arms 34 and 35 are connected to bendable at the joint portion 2. One end portion of the first arm 34 is connected to the vehicle body 33 at the joint portion 2, and the base portion of the second arm 35 is connected to the other end portion of the arm 34 at the joint portion 2. The first arm 34 is rotated around the joint portion 2 on the vehicle body 33 side by the cylinder 36, and the second arm 35 is rotated around the joint portion 2 of the base portion by the cylinder 37. Further, the excavator 38 is swingably connected to the tip of the second arm 35 at the joint portion 2 and is driven to swing by a wire (not shown). In this case, in order to control the operation of the tips of the arms 34 and 35 and to prevent interference with the vehicle body 33, the rotation angle detection device 6 (FIG. 3) in the first embodiment is provided on each joint portion 2. Or the bearing 5 (FIG. 2) with a rotation detection apparatus is mounted, and the rotation angle of the arms 34 and 35 is detected. The vehicle body 33 is installed on the traveling crawler 39 so as to be turnable via the turning shaft 40. The rotation angle detection device 6 (FIG. 3) detects the turning angle of the vehicle body 33 also on the turning shaft 40. Is provided. For example, a turntable bearing (not shown), which is a thin large-diameter ring bearing, is used to support the turning shaft 40.

  Thus, when the rotation angle detection device 6 is mounted on the shovel car 25 that is an articulated machine, even if the magnetic intensity of the magnetism generating means 28 (FIG. 3) in the rotation angle detection device 6 changes due to a temperature change, the angle Since it can be detected and is a non-contact method, it is possible to detect the rotation angle with high reliability. Further, instead of directly mounting the rotation angle detection device 6 on each joint portion 2, the bearing 5 with the rotation detection device (FIG. 2) in the first embodiment in which the rotation angle detection device 6 and the bearing are integrated. In this case, it can be mounted compactly and no assembly adjustment is required. Further, by connecting each rotation angle detection device 6 with the rotation angle detection device connector 10 (FIG. 5) in the first embodiment, the wiring of the cable to the tip of the arm 35 can be reduced.

  FIG. 10 shows an example of a rotation angle detection device 41 of a magnetic array sensor / potentiometer combination type used in a machine with a turning axis such as a construction machine. The turning shaft 42 is a stepped shaft, and the shaft large-diameter portion 42 a is rotatably supported by two bearings 44 fitted into the housing 43. A small shaft diameter portion 42 b at one end of the turning shaft 42 protrudes outside from a hole in the top plate portion of the housing 43. The other end of the pivot shaft 42 has a stepped shape, and a ring-shaped bearing width presser 45 and a brush assembly 46 are arranged concentrically with each other and fixed with screws. A brush 46a is attached to the brush assembly 46 in the axial direction. Further, in the center of the other end of the turning shaft 42, the magnetism generating means 28 of the rotation angle detecting device 6 (FIG. 3) in the first embodiment is fixed.

  The housing 43 is formed in a bowl-shaped cylinder having an end wall at the upper end, and has a flange 43a on the outer periphery of the opening at the lower end, and the lower end opening is closed by a presser lid 47 that is a lid. The presser lid 47 is fitted to a countersunk portion provided at the periphery of the lower end opening of the housing 43 and fixed to the housing 43 with screws. The presser cover 47 pushes the outer ring of the bearing 44 through a ring-shaped spacer 48 fitted to the inner diameter surface of the housing 43 following the countersunk portion. A sealing resin 49 is provided on the outer surface of the presser lid 47.

  On the inner surface of the presser lid 47, an electric resistor 50a and an electrode 50b constituting the potentiometer 50 are provided in a concentric ring shape at a radial position corresponding to the brush assembly 46. The electric resistor 50 a and the electrode 50 b are provided on the circuit board 51 fixed to the presser lid 47. Since it is necessary to apply a preload to the brush assembly 46 brought into contact with the potentiometer 50, a certain degree of accuracy is ensured in the gap between the shaft end of the pivot shaft 42 and the circuit board 51. In the center of the potentiometer arrangement surface of the circuit board 51, an angle detector 8 including a magnetic array sensor 29 (FIG. 3) of the rotation angle detector 6 is provided at a position corresponding to the magnetism generating means 28. The brush assembly 50 on the swivel shaft 42 side and the potentiometer 50 on the presser cover 47 side constitute a contact-type rotation angle detection unit 52 different from the non-contact type rotation angle detection unit 6.

  The rotation angle detection device 41 is a circuit in which a magnetic array sensor in which magnetic sensor elements are arranged in an array is mounted on a circuit board 51 on which an electrical resistor 50a of a contact sensor is printed. Two types of sensors can be mounted on the substrate 51. Since it is necessary to apply a preload to the electrode 50b to be brought into contact with the electric resistor 50a, it is necessary to ensure a certain degree of accuracy in the gap between the shaft end and the circuit board 51. In the case of the non-contact type rotation angle detection device 6, since it is difficult to be affected by the gap change, it is not necessary to manage the gap again.

  A back plate 53 is fixed at a position away from the outer surface of the presser lid 47. The space between the presser lid 47 and the back plate 53 is hardened with the sealing resin 49 after the adjustment inspection. The cable 54 connected to the circuit board 51 is led out of the housing 43 in the radial direction, and is connected to an external device (both not shown) via a connector.

According to this configuration, since the contact-type rotation angle detection device unit 52 and the non-contact-type rotation angle detection device 6 are combined, highly reliable rotation angle detection is possible.
In such a machine 41 with a turning shaft, in order to detect the rotation angle of the turning shaft 42, the rotation angle is detected in a non-contact manner by arranging a magnetic sensor such as a Hall sensor on the outer peripheral surface of the turning shaft 42. However, in this case, it is necessary to make the arrangement radius of the magnetic sensor as large as possible in order to secure the detection capability, and it is difficult to make it compact. In addition, since the magnetic sensor is arranged near the outer peripheral surface and a signal processing circuit is required separately, the number of parts increases. Furthermore, since the rotation angle is detected on the outer peripheral surface, it is difficult to detect the absolute angle.
On the other hand, in the case of this embodiment, rotation detection is performed using the end face of the turning shaft 42, so that the outer peripheral surface of the turning shaft 42 does not have to be used for detecting the rotation angle. Therefore, the apparatus can be miniaturized, the absolute rotation angle can be detected with high resolution, and the function and compactness of the apparatus can be realized.

  FIG. 11 shows still another embodiment of the present invention. In this embodiment, in the embodiment of FIG. 10, the shaft end of the pivot shaft 42 facing the presser lid 47 is set as the shaft minimum diameter portion 42 c, and this shaft minimum diameter portion 42 c is integrated with the rotation angle detection device 6 and the bearing. The support lid 47 supports the rotation detecting device-equipped bearing 5 (FIG. 2) in the first embodiment. In this case, the angle detector 8 fixed to the sensor attachment member 27 attached to the outer ring 22 as in FIG. 2 is fixed at a position facing the magnetism generating means 28 fixed to the rotating member. The lead wire 55 from the angle detection unit 8 is led out to the outside of the housing 43 together with the cable 54 connected to the circuit board 51, and is connected to an external device (none of which is shown) via a connector. The Other configurations are the same as those in the embodiment of FIG.

  According to this configuration, the non-contact rotation angle detection device 6 is unitized with the bearing as the rotation detection device-equipped bearing 5, so that troubles such as mounting on the circuit board 51 are not required, and maintenance is improved.

1 is a cable connection diagram of an articulated robot equipped with a rotation angle detection device according to a first embodiment of the present invention and its control device. It is sectional drawing which shows an example of the bearing with a rotation detection apparatus mounted in the articulated robot. It is a perspective view which shows the conceptual structure of the rotation angle detection apparatus in the bearing with the rotation detection apparatus. It is a top view which shows the example of arrangement | positioning of the magnetic array sensor and angle calculation means on a semiconductor chip in the rotation angle detection apparatus. It is a block diagram of the rotation angle detection apparatus connection body applied to an articulated robot. It is explanatory drawing of the information transmission operation | movement in the rotation angle detection apparatus connection body. It is a cable connection figure of the articulated hand carrying the rotation angle detection apparatus concerning other embodiment of this invention, and its control apparatus. It is a perspective view of the joint part carrying the rotation angle detection apparatus concerning further another embodiment of this invention. It is a side view of the shovel car which mounts the rotation angle detection apparatus concerning further another embodiment of this invention. It is sectional drawing of the machine with a rotating shaft carrying the rotation angle detection apparatus concerning further another embodiment of this invention. It is sectional drawing of the machine with a rotating shaft carrying the rotation angle detection apparatus concerning further another embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Articulated robot 2 ... Joint part 3 ... Arm part (joint component)
DESCRIPTION OF SYMBOLS 5 ... Bearing 6, 6A-6D with rotation detection apparatus ... Rotation angle detection apparatus 8 ... Angle detection part 9a ... Data communication part 9 ... Data transmission means 10 ... Rotation angle detection apparatus connector 11, 12 ... Joint component 15 ... Many Joint hand 25 ... excavator 28 ... magnetism generating means 29 ... magnetic array sensor 30 ... angle calculating means 34, 35 ... arm 41 ... rotation angle detecting device 42 ... turning shaft 52 ... rotating angle detecting device section

Claims (5)

  In an articulated machine such as a construction machine or an industrial machine having a joint part, it is a device for detecting a rotation angle of the joint part, and is one of a pair of freely rotatable joint constituent members constituting the joint part. A magnetic generating means provided on a joint constituent member or a member integrated with the joint constituent member and having circumferential anisotropy around the center of rotation, and facing the axial direction of the center of rotation of the magnetic generating means A magnetic array sensor that is provided on one joint constituent member or a member integrated with the joint constituent member and detects the magnetism of the magnetism generating means, and the rotation angle of the magnetism generating means is calculated from the output of the magnetic array sensor. A rotation angle detecting device comprising an angle calculating means.   2. A pair of mutually rotatable joint constituent members constituting the joint portion are connected to each other through a bearing, and the bearing includes the magnetic generating means and the magnetic array sensor. The rotation angle detection apparatus which is a bearing with a rotation detection apparatus provided with the angle detection part which has.   In a machine with a pivot axis, such as a construction machine having a pivot axis, a device for detecting the rotation angle of the pivot axis, provided on the pivot axis or a member that pivots integrally with the pivot axis, and a circle around the pivot center A magnetism generating means having circumferential anisotropy, a magnetic array sensor provided on a non-swivel side member facing the axial direction of the turning center of the magnetism generating means to detect magnetism of the magnetism generating means, and the magnetism A rotation angle detection device comprising: an angle calculation unit that calculates a rotation angle of the magnetism generation unit from an output of the array sensor.   The rotation detection device according to claim 3, wherein the pivot shaft is rotatably supported via a bearing, and the bearing is a bearing with a rotation detection device provided with an angle detection unit having the magnetism generation unit and a magnetic array sensor. A rotation angle detection device.   5. A rotational angle detection device connecting body provided with a plurality of rotation angle detection devices according to claim 1 and provided with data transmission means for transmitting and receiving signals between the plurality of rotation angle detection devices. .

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