JP2014210330A - Robot finger unit, robot hand, and robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a robot finger unit which detects a load acting on a finger tip from the lateral side when holding a work-piece and inhibits damages of a pressure-sensitive sensor even if an excessive load acts thereon, and to provide a robot hand and a robot.SOLUTION: A robot finger unit includes: a case 43 of a finger 40 provided at a robot; a first swing member 44 which is provided ranging from the base end side to the tip side of the case 43 and is supported by the case 43 so as to swing with a center part set as a first supporting point 44a, the first swing member 44 including a pressure receiving part 44b which is disposed at the tip side and receives a load and a transmission part 44c which is disposed at the base end side and transmits the load; a facing part 48 which is supported by the case 43 and faces the transmission part 44c; a pressure-sensitive sensor 45 disposed between the transmission part 44c and the facing part 48; and an elastic part 46 which elastically deforms and thereby reduces a pressurizing force generated by the load and acting on the pressure-sensitive sensor 45.

Description

  The present invention relates to a robot finger unit suitable for use in a multi-joint arm robot hand driven by controlling a plurality of joints, and a robot hand and a robot using the robot finger unit.

  Conventionally, a robot apparatus including a vertical articulated arm and an end effector (hereinafter referred to as a robot main body) and a control device for controlling them has been widely used. As an end effector, a plurality of fingers are used to hold a workpiece. Possible robot hands are widespread. In a robot hand, in order to detect whether or not a workpiece is gripped or to detect a gripping force (load) for gripping a workpiece, it is desired to include a pressure-sensitive sensor at the fingertip.

  As a pressure-sensitive sensor, a sensor having a pressure receiving member that receives a load from the outside and a sensor unit that measures the applied pressure when the load is transmitted from the pressure receiving member is widely used. Further, in order to prevent the sensor portion from being damaged due to an excessive load from the pressure receiving member, when the pressure receiving member receives an excessive load, the pressure receiving member is separated from the sensor portion and the load is applied to the sensor portion. There is known a sensor device that does not act (see Patent Document 1).

  However, since the pressure-receiving member reciprocates linearly, a structure such as a sensor unit or a return spring must be disposed in the vicinity of an extension line in the load acting direction. On the other hand, at the tip of the finger of the robot hand, it is necessary to measure the load acting perpendicular to the longitudinal direction of the finger when gripping the workpiece. When it is provided in the case, it is necessary to increase the size of the finger, which is difficult to implement.

  On the other hand, there is known a switch device that includes a seesaw rod that can be swung with a center part as a swing center, one end of the seesaw rod can be pressed in a swinging direction by a push rod, and a detection switch is turned on / off by the other end (See Patent Document 2). According to this switch device, since the load can be transmitted from the push rod to the detection switch via the seesaw rod, the detection switch can be arranged in a direction different from the pressing direction of the push rod. Can be installed without increasing the size.

JP 7-260604 A JP 2006-216265 A

  However, in the switch device described in Patent Document 2, when a load is applied from the push rod to one end of the seesaw rod, the other end of the seesaw rod swings away from the detection switch. As a result, even if a pressure sensor is provided instead of the detection switch, if the load is large, the seesaw rod will be separated from the pressure sensor and it will not be possible to measure a larger load. If the seesaw rod and the pressure sensor are fixed so as not to be separated from each other, when an excessive load is applied from the push rod, the load is transmitted to the pressure sensor via the seesaw rod and the pressure sensor is damaged. There is a possibility that.

  The present invention provides a robot finger unit, a robot hand, and a robot that can detect a load acting from the side on the tip of a finger when gripping a workpiece and can suppress damage to a pressure sensor even when an excessive load is applied. The purpose is to provide.

  The robot finger unit according to the present invention is provided from the base end side to the tip end side of the finger main body provided in the robot, and supported swingably on the finger main body with the central portion serving as a first fulcrum. And a first receiving member disposed on the distal end side for receiving a load, a first swinging member disposed on a proximal end side for transmitting the load, and supported by the finger body. An opposing facing portion; a pressure-sensitive sensor disposed between the transmitting portion and the facing portion; and an elastic portion that reduces the pressure applied to the pressure-sensitive sensor by the load by elastic deformation. It is characterized by that.

  According to the present invention, the first swing member is provided from the proximal end side to the distal end side of the finger main body, and the load from the side when gripping the workpiece is transmitted to the pressure sensitive sensor by swinging. Therefore, the load acting on the tip of the finger can be detected. In addition, since the elastic portion is elastically deformed, the pressure applied to the pressure sensor is reduced based on the external load, so that the pressure sensor is prevented from being damaged even if an excessive load is applied to the fingertip. Can do.

It is explanatory drawing which shows schematic structure of the robot apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the robot finger unit which concerns on embodiment of this invention, (a) is a perspective view, (b), (c), (d) is a rocking | fluctuating member rock | fluctuates when holding a workpiece | work. Sectional drawing which shows order, (e) is a top view which shows the position of the contact line of the press part in a pressure sensor. It is sectional drawing which shows the robot finger unit which concerns on embodiment of this invention, (a) is a case where a compression coil spring is used, (b) is a case where rubber is used, (c) is elastically deformed to a rocking | swiveling member. (D) shows a case where a pressure sensitive sensor is provided on the swing member.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the robot apparatus 1 includes a robot 2 and a control device 3 that controls the robot 2.

  The robot 2 has a 6-axis vertical articulated arm (hereinafter referred to as an arm) 5 and a hand (robot hand) 4 as an end effector. In the present embodiment, a 6-axis vertical articulated arm is applied as the arm 5, but the number of axes may be appropriately changed according to the application and purpose.

  The arm 5 includes seven links 61 to 67 and six joints 71 to 76 that connect the links 61 to 67 so as to swing or rotate. As each of the links 61 to 67, one having a fixed length is adopted. However, for example, a link that can be expanded and contracted by a linear actuator may be employed. Each joint 71 to 76 includes a motor that drives each of the joints 71 to 76, an encoder that detects a rotation angle of the motor, a current sensor that detects a current supplied to each motor, and a torque of each joint 71 to 76. And a torque sensor for detecting.

  The hand 4 is attached to and supported by the distal end link 67 of the arm 5, and at least one degree of freedom in position and posture is adjusted by the operation of the arm 5. The hand 4 includes two fingers 40 and 41 and a hand main body 42 that supports the distance between the fingers 40 and 41 so as to be openable and closable so that the workpiece W can be gripped by a closing operation in which the fingers 40 and 41 approach each other. It has become. One finger (robot finger unit) 40 has a built-in pressure-sensitive sensor 45 to be described later, and can measure a gripping force acting on the finger 40 when the workpiece W is gripped. The other finger 41 does not incorporate the pressure sensor 45 and has only a function for gripping the workpiece W.

  The hand main body 42 is provided with a motor for operating the fingers 40, 41, an encoder for detecting the rotation angle of the motor, and a connecting portion connected to the tip link 67. In the present embodiment, the hand 4 has two fingers 40 and 41. However, the present invention is not limited to this, and the number of fingers may be two or more in order to grip the workpiece W.

  The control device 3 is configured by a computer and controls the robot 2. The computer constituting the control device 3 includes, for example, a CPU, a ROM that stores a program for controlling each unit, a RAM that temporarily stores data, an input interface circuit, and an output interface circuit.

  Next, the finger 40 which is a characteristic part of the robot apparatus 1 according to the present embodiment will be described in detail with reference to FIG.

  The finger 40 includes a swing member (first swing member) 44 along the longitudinal direction inside the case (finger main body) 43, a pressure-sensitive sensor 45 pressed by the swing member 44, A leaf spring (elastic portion, plate member) 46 that supports the pressure sensor 45 with respect to the case 43 is provided.

  The case 43 has a substantially cylindrical shape with a rectangular cross section, and is a rigid body made of a material having such a rigidity that hardly deforms even when a load is applied from the outside, such as metal or synthetic resin. A claw portion 43a is formed at the tip of the case 43 so as to protrude from the side opposite to the opposing finger 41 (outside of the finger 40) to the tip, so that the workpiece W can be positioned and gripped with high accuracy. It is like that. When the workpiece W is gripped, a load is applied to the claw portion 43a perpendicular to the longitudinal direction of the finger 40 and directed outward. A groove 43b that communicates with the inside of the case 43 along the longitudinal direction is formed in the central portion inside the claw portion 43a, and the pressure receiving portion 44b of the swing member 44 is accommodated in the groove 43b.

  The swinging member 44 is supported by the case 43 so as to be swingable from the proximal end side to the distal end side of the case 43 with the substantially central portion serving as the first fulcrum 44a. Further, the swing member 44 is a rigid body made of a material having such a rigidity that hardly deforms even when a load is applied from the outside, such as metal or synthetic resin.

  The swing member 44 is disposed on the distal end side, receives a gripping force (load) when gripping the workpiece W from the side of the case 43, and is disposed on the proximal end side to transmit a load. It is equipped with. The position of the first fulcrum 44a is substantially the center in the present embodiment, but is not limited to this, and may be anywhere as long as it is a portion (central portion) between the pressure receiving portion 44b and the transmission portion 44c. It can be set as appropriate based on the relationship between the load to be detected and the force and stroke of the pressure-sensitive sensor 45.

  The pressure receiving part 44b can be projected and retracted with respect to the groove 43b of the claw part 43a as the swinging member 44 swings. When protruding, the pressure receiving part 44b receives the load from the gripped workpiece W and is pushed into the groove 43b. (See FIGS. 2B to 2D).

  The transmission portion 44c is disposed to face the pressure sensor 45, and a pressing portion 47 capable of pressing the pressure sensor 45 toward the pressure sensor 45 side is provided. The pressing portion 47 is formed integrally with the transmission portion 44c, has a shape protruding toward the pressure-sensitive sensor 45, and has a cylindrical surface shape having a central axis parallel to the first fulcrum 44a. Since the pressing portion 47 has a cylindrical surface shape, when the pressing portion 47 presses the pressure-sensitive sensor 45 when gripping the workpiece W, the pressure-sensitive sensor 45 is stably linearly pressed. The pressing portion 47 and the swing member 44 are integrally formed. However, the present invention is not limited to this, and the pressing portion 47, which is a member different from the swing member 44, is attached to the transmission portion 44c by bonding or the like. May be. Further, the shape of the pressing portion 47 is not limited to the cylindrical surface shape, and can be appropriately set such as a prismatic surface shape or a planar shape. Furthermore, the pressing portion 47 is not necessarily provided.

  The pressure-sensitive sensor 45 is a pressure-sensitive conductive rubber sensor, and is disposed so as to face the pressing portion 47. The pressure-sensitive conductive rubber sensor contains conductive particles in rubber, and there is no or little contact between the conductive particles contained in the rubber when no load is applied to the member. High resistance state. When a load acts on the pressure-sensitive conductive rubber, the rubber is distorted, the conductive particles approach each other, and the number of conductive particles in contact increases, so the electrical resistance decreases. Thus, the pressure-sensitive conductive rubber sensor functions as a pressure-sensitive sensor by utilizing the characteristic that the electric resistance changes according to the load.

  The pressure sensor 45 is connected to the CPU, and the CPU reads a resistance value that changes according to the load received by the pressure sensor 45. Thus, the CPU can measure the magnitude of the load acting on the pressure sensor 45, and controls the operation of the robot 2 based on the measurement result.

  The leaf spring 46 is made of an elastically deformable metal or a resin such as rubber or plastic. Is attached by adhesion or the like so as to contact the pressing portion 47. The leaf spring 46 may be a member made of a single material, or may be a member integrated by molding or the like such that both ends are made of a rigid metal and the center is made of an elastic resin. In addition, the side surface to which the pressure sensor 45 of the leaf spring 46 is attached is the facing portion 48 of the present invention.

  Since the pressure-sensitive sensor 45 and the pressing portion 47 are in contact with each other, the swing member 44 is urged in the counterclockwise rotation direction in FIG. For this reason, when no load is applied to the pressure receiving portion 44b from the workpiece W, for example, as shown in FIG. 2B, the leaf spring 46 is minimally curved and the pressure receiving portion 44b protrudes greatly from the groove 43b. ing. On the other hand, when a large load is applied to the pressure receiving portion 44b from the workpiece W, for example, as shown in FIG. 2D, the pressure receiving portion 44b is pushed into the groove 43b and the leaf spring 46 is greatly curved. It has become. Thereby, compared with the case where the pressure sensor 45 is directly fixed to the case 43, it becomes possible to suppress damage due to an excessive load.

  An operation of detecting the gripping force by the finger 40 when the workpiece W is gripped using the fingers 40 and 41 of the robot apparatus 1 described above will be described below.

  The pressure sensor 45 is calibrated in advance. In this calibration work, the error due to the elastic deformation by the leaf spring 46 is calibrated from the pressure applied to the pressure sensor 45. The calibration method is not particularly limited. For example, as in the existing pressure-sensitive sensor calibration method, the measured value of the reference pressure sensor may be used by pressing against a known reference pressure sensor. .

  When the hand 4 grips the workpiece W, the arm 5 takes a position and orientation such that the workpiece W is positioned between the two fingers 40 and 41, and the hand 4 brings the two fingers 40 and 41 closer to each other. The workpiece W is gripped by the fingers 40 and 41.

  When the fingers 40 and 41 are closed with the workpiece W interposed therebetween, as shown in FIG. 2B, when the workpiece W comes into contact with the pressure receiving portion 44b, the pressure receiving portion 44b greatly protrudes from the groove 43b. The curvature of the leaf spring 46 is minimized. At this time, since the pressure applied from the pressing portion 47 to the pressure sensor 45 is minimum, the resistance value of the pressure sensor 45 is maximum. In addition, the contact line with the press part 47 in the pressure sensor 45 at this time, ie, a press position, is shown with the code | symbol 45a in the figure.

  Then, when the closing operation of the fingers 40 and 41 proceeds, as shown in FIG. 2C, the workpiece W comes to press the pressure receiving portion 44b. As a result, the pressure receiving portion 44b is gradually pushed into the groove 43b, the swinging member 44 is inclined, and the curvature of the leaf spring 46 gradually increases, and the pressure applied from the pressing portion 47 to the pressure sensor 45 gradually increases. Since it increases, the resistance value of the pressure-sensitive sensor 45 decreases. The amount of elastic deformation of the leaf spring 46 changes according to the magnitude of the load acting on the pressure receiving portion 44b. In addition, the position of the contact line with the press part 47 in the pressure sensor 45 at this time is shown with the code | symbol 45b in the figure.

  Further, when the closing operation of the fingers 40 and 41 proceeds, as shown in FIG. 2D, the work W greatly pushes the pressure receiving portion 44b and comes into contact with the side surface of the claw portion 43a. As a result, the pressure receiving portion 44b is pushed most greatly into the groove 43b, the swinging member 44 is further inclined, and the leaf spring 46 is bent most, and the pressing force from the pressing portion 47 to the pressure sensor 45 is further increased. As a result, the resistance value of the pressure sensor 45 is minimized. In addition, the position of the contact line with the press part 47 in the pressure sensor 45 at this time is shown with the code | symbol 45c in the figure.

  The CPU measures the resistance value of the pressure-sensitive sensor 45 at a desired time, and calculates the gripping force of the fingers 40 and 41 at that time based on the obtained measurement value and the calibration value obtained in advance. The operation of the robot 2 is controlled based on the result. Here, the CPU obtains the value of the gripping force with the fingers 40 and 41. However, the present invention is not limited to this. For example, for detecting whether or not the fingers 40 and 41 are gripping the workpiece W. It can also be used as an on / off switch.

  Thus, as the workpiece W presses the pressure receiving portion 44b, the swinging member 44 swings in the clockwise direction in FIG. 2, and the pressing portion 47 presses the pressure sensitive sensor 45, and the leaf spring 46 is pressed. Is bent by elastic deformation so as to swing on the tip side. Since the pressure-sensitive sensor 45 is supported by the leaf spring 46, damage due to an excessive load is suppressed as compared with the case where it is directly fixed to the case 43.

  Here, from the viewpoint of preventing an overload on the pressure sensor 45, when a maximum load is applied to the pressure receiving part 44b, the pressure applied to the pressure sensor 45 by the pressing part 47 is less than the load resistance of the pressure sensor 45. It is necessary to do so. In the present embodiment, the pressure applied to the pressure sensor 45 by the pressing portion 47 when a load is applied from the outside is reduced by the elastic deformation of the leaf spring 46. Thus, the material, shape, and thickness of the leaf spring 46 are adjusted so that the pressure applied to the pressure sensor 45 by the pressing portion 47 is less than the load resistance of the pressure sensor 45 when the maximum load is applied. By setting the spring constant, overload to the pressure-sensitive sensor 45 is prevented.

  Moreover, as shown in FIG.2 (e), the position of the contact lines 45a-45c with the press part 47 in the pressure sensor 45 moves according to the magnitude | size of a load. This is a position where the first fulcrum 44a of the swing member 44 and the rotation center of the leaf spring 46 (cantilever supported portion) are different, and the pressure sensor 45 and the pressing portion 47 are displaced from each other. This is due to the rocking. In particular, in the present embodiment, each point is located on the opposite side across the contact point between the pressing portion 47 and the pressure-sensitive sensor 45, so that the pressure-sensitive sensor 45 and the pressing portion 47 swing in a direction away from each other. Even if the swing angle is small, the positions of the contact lines 45a to 45c move relatively large.

  As described above, the position of the contact lines 45a to 45c of the pressure sensor 45 changes depending on the magnitude of the load, so that the deterioration of the pressure sensor 45 due to pressure reception is caused by the contact surface between the pressure sensor 45 and the pressing portion 47. Accordingly, the pressure sensor 45 can be prevented from being deteriorated and the life thereof can be extended.

  As described above, according to the finger 40 of the present embodiment, the swing member 44 is provided from the proximal end side to the distal end side of the case 43, and the load from the side when gripping the workpiece W swings. Therefore, the load acting on the tip of the finger 40 can be detected. Further, since the leaf spring 46 is elastically deformed, the pressure applied to the pressure-sensitive sensor 45 is reduced based on an external load, so that even if an excessive load is applied to the fingertip, the pressure-sensitive sensor 45 is damaged. Can be suppressed.

  Here, in the pressure-sensitive sensor 45, a change in shape, thickness, or the like may occur on the contact surface pressed by the pressing portion 47 of the pressure-sensitive sensor 45 due to repeated pressing or aging deterioration. On the other hand, according to the finger 40 of the present embodiment, both the pressing portion 47 and the pressure-sensitive sensor 45 swing, and the swing center is different. For this reason, since the deformation amount of the leaf spring 46 having elasticity when the pressure sensor 45 is pressed changes according to the change in the shape of the contact surface of the pressure sensor 45, the contact lines 45a to 45c of the pressure sensor 45 are changed. The position also changes.

  Therefore, even when a change occurs in the shape and thickness of the contact surface of the pressure-sensitive sensor 45, the pressure position of the pressure-sensitive sensor 45 can be reliably changed when an external load is applied to the pressure-receiving portion 44b. The sensor 45 can be pressed. As a result, the deterioration of the pressure-sensitive sensor 45 caused by pressure reception can be widely dispersed on the contact surface of the pressure-sensitive sensor 45, and the deterioration of the pressure-sensitive sensor 45 can be prevented and the life can be extended.

  Further, according to the finger 40 of the present embodiment, since the pressing portion 47 has a cylindrical surface shape, when the pressing portion 47 and the pressure sensor 45 come into contact, the pressing portion 47 is plate-shaped and its end portion is The contact area can be increased compared to the case of contact. As a result, the deterioration of the pressure-sensitive sensor 45 caused by pressure reception can be more widely dispersed on the contact surface of the pressure-sensitive sensor 45, and the deterioration of the pressure-sensitive sensor 45 can be prevented and the life can be extended.

  In the present embodiment described above, the case where the plate spring 46, which is a plate member, is applied as the elastic portion has been described. However, the present invention is not limited to this. For example, as shown in FIG. 3A, a support member (second swing member) 51 that can swing around a second fulcrum 51 a supported by the case 43 is provided, and the support member 51 is pressed. The pressure sensor 45 may be provided on the part 47 side, and the compression coil spring 52 may be provided on the opposite side. The support member 51 is made of a material having such a rigidity that hardly deforms even when a load is applied from the outside, such as metal or synthetic resin. In this case, the compression coil spring becomes the biasing member and the elastic portion of the present invention, and the side surface of the support member 51 to which the pressure sensitive sensor 45 is attached becomes the facing portion 48 of the present invention.

  Also in this case, since the compression coil spring 52 is elastically deformed, the pressure applied to the pressure sensor 45 due to the load is reduced, so that damage to the pressure sensor 45 is suppressed even if an excessive load is applied to the fingertip. be able to. Also in this case, since both the pressing portion 47 and the pressure sensitive sensor 45 swing and the swing centers are different, the contact lines of the pressing portion 47 and the pressure sensitive sensor 45 move due to the load. For this reason, the deterioration of the pressure-sensitive sensor 45 caused by pressure reception can be widely dispersed on the contact surface of the pressure-sensitive sensor 45, and the deterioration of the pressure-sensitive sensor 45 can be prevented and the life can be extended. Moreover, since the support member 51 is a rigid body and does not elastically deform, the pressure sensor 54 can be stably supported.

  Further, for example, as shown in FIG. 3B, an elastic body (elastic portion) 53 supported by the case 43 is provided, and a pressure-sensitive sensor 45 is provided on the pressing portion 47 side of the elastic body 53. Good. The elastic body 53 is made of an elastically deformable material such as a resin such as rubber. In this case, the side surface to which the pressure-sensitive sensor 45 of the elastic body 53 is attached becomes the facing portion 48 of the present invention. Also in this case, the elastic body 53 is elastically deformed to reduce the pressure applied to the pressure-sensitive sensor 45 by the load, so that damage to the pressure-sensitive sensor 45 is suppressed even if an excessive load is applied to the fingertip. Can do.

  In the present embodiment, the swing member 44 is a rigid body, but is not limited thereto. For example, as shown in FIG. 3C, a thin spring portion (elastic deformation portion, elastic portion) 44d is formed between the first fulcrum 44a and the transmission portion 44c, and the spring portion 44d is elastically deformed. You may make it do. The spring portion 44d is not limited to a thin shape as long as the spring portion 44d has a structure that is more easily elastically deformed than other portions of the swing member 44. In this case, when a load is applied, both the leaf spring 46 and the spring portion 44d are elastically deformed, so that the relative swing angle between the pressing portion 47 and the pressure sensor 45 becomes larger, and the contact line moves. The amount gets bigger. As a result, the deterioration of the pressure-sensitive sensor 45 caused by pressure reception can be further widely dispersed on the contact surface of the pressure-sensitive sensor 45, and the deterioration of the pressure-sensitive sensor 45 can be prevented and the life can be extended.

  Here, when the spring portion 44 d is provided between the first fulcrum 44 a and the transmission portion 44 c, the pressure sensor 45 may be directly attached to the case 43 without using the leaf spring 46. In this case as well, since the spring portion 44d is elastically deformed, the pressure applied to the pressure sensitive sensor 45 due to the load is reduced, so that damage to the pressure sensitive sensor 45 is suppressed even if an excessive load acts on the fingertip. Can do. Also in this case, since the pressing portion 47 swings, the contact line between the pressing portion 47 and the pressure-sensitive sensor 45 moves due to the load. For this reason, the deterioration of the pressure-sensitive sensor 45 caused by pressure reception can be widely dispersed on the contact surface of the pressure-sensitive sensor 45, and the deterioration of the pressure-sensitive sensor 45 can be prevented and the life can be extended.

  Further, as indicated by an imaginary line in FIG. 3C, a thin spring portion (elastic deformation portion, elastic portion) 44e may be provided between the first fulcrum 44a and the pressure receiving portion 44b. In this case, the leaf spring 46 and the spring portion 44d may or may not be provided. Even when the leaf spring 46 and the spring portion 44d are not provided, the spring portion 44e is elastically deformed to reduce the pressure applied to the pressure-sensitive sensor 45 by the load, so that even if an excessive load is applied to the fingertip, Damage to the pressure sensor 45 can be suppressed.

  In the present embodiment, the case where the pressing member 47 is provided on the swing member 44 and the pressure-sensitive sensor 45 is provided on the case 43 side has been described. However, the present invention is not limited thereto. For example, as shown in FIG. 3D, a pressure sensor 45 may be provided in the transmission portion 44 c and a pressing portion 47 may be provided in the leaf spring 46.

  Also in this case, since the leaf spring 46 is elastically deformed, the pressure applied to the pressure-sensitive sensor 45 due to the load is reduced, so that damage to the pressure-sensitive sensor 45 is suppressed even if an excessive load is applied to the fingertip. Can do. Also in this case, since both the pressing portion 47 and the pressure-sensitive sensor 45 swing and the swing centers are different, the contact lines of the pressing portion 47 and the pressure-sensitive sensor 45 move due to the load. For this reason, the deterioration of the pressure-sensitive sensor 45 caused by pressure reception can be widely dispersed on the contact surface of the pressure-sensitive sensor 45, and the deterioration of the pressure-sensitive sensor 45 can be prevented and the life can be extended. Moreover, since the transmission portion 44c is a rigid body and does not elastically deform, the pressure sensitive sensor 54 can be stably supported.

  As described above, the pressure-sensitive sensor 45 may be disposed between the facing portion 48 supported by the case 43 and the transmission portion 44 c that is a part of the swing member 44. Moreover, the arrangement | positioning location of an elastic part is not limited, What is necessary is just to reduce the applied pressure which acts on the pressure sensor 45 with a load by elastic deformation. Furthermore, the pressure-sensitive sensor 45 may be disposed on one of the transmission part 44 c and the facing part 48, and the pressing part 47 may be disposed on the other of the transmission part 44 c and the facing part 48.

  In the present embodiment, the case where a pressure-sensitive conductive rubber sensor is applied as the pressure-sensitive sensor 45 has been described. However, the present invention is not limited to this, and any sensor that detects a pressed force may be used depending on the application. A sensor with a detection principle can be used. For example, the conductive elastomer sensor may be used in general, or other strain gauges may be applied.

  Further, in the present embodiment, the pressure receiving portion 44b is exposed from only one location at the tip of the case 43, but is not limited to this, and the inner side of the tip of the case 43 is formed in a step shape, so that a plurality of steps are provided. You may make it expose from a part. In this case, when a workpiece W having a different size is gripped using different step portions, the gripping force can be detected regardless of which step portion is gripped.

  In the present embodiment, the case where only one of the two fingers 40 and 41 of the hand 4 has the pressure-sensitive sensor 45 has been described. However, the present invention is not limited to this. May include a pressure-sensitive sensor 45. Further, even if the hand 4 has three or more fingers, it is sufficient that at least one finger 40 has the pressure sensor 45, but a plurality of fingers may have pressure sensors. Good.

2 ... robot, 4 ... hand (robot hand), 40 ... finger (robot finger unit), 43 ... case (finger body), 44 ... swing member (first swing member), 44a ... first fulcrum, 44b ... pressure receiving part, 44c ... transmission part, 44d ... spring part (elastic part, elastic deformation part), 44e ... spring part (elastic part, elastic deformation part), 45 ... pressure sensor, 46 ... leaf spring (elastic part, Plate member), 48 ... opposing portion, 51 ... support member (second swing member), 51a ... second fulcrum, 52 ... compression coil spring (elastic portion, biasing member), 53 ... elastic body (elastic portion) )

Claims (10)

A finger body provided on the robot;
A pressure receiving portion provided from the proximal end side to the distal end side of the finger body, supported by the finger body so as to be swingable with a central portion serving as a first fulcrum; A first oscillating member that is disposed on an end side and has a transmission portion that transmits the load;
An opposing portion supported by the finger body and facing the transmission portion;
A pressure sensitive sensor disposed between the transmitting portion and the facing portion;
An elastic part that reduces the applied pressure acting on the pressure sensor by the load by elastic deformation,
Robot finger unit characterized by that. The pressure sensor is disposed on one of the transmission unit and the facing unit, and a pressing unit capable of pressing the pressure sensor is disposed on the other of the transmission unit and the facing unit.
The robot finger unit according to claim 1. The pressing portion has a shape protruding toward the pressure-sensitive sensor and a cylindrical surface shape having a central axis parallel to the first fulcrum.
The robot finger unit according to claim 2. The pressure-sensitive sensor is a pressure-sensitive conductive rubber sensor.
The robot finger unit according to any one of claims 1 to 3, wherein the robot finger unit is provided. While having the facing portion on the side facing the transmitting portion, cantilevered by the finger body, provided with a plate member that can be elastically deformed,
The elastic part is composed of the plate member.
The robot finger unit according to any one of claims 1 to 4, wherein the robot finger unit is provided. A second oscillating member having the opposing part on a side surface facing the transmission part, having a second fulcrum, and supported by the finger body so as to be oscillatable around the second fulcrum;
An elastically deformable urging member that urges the second swinging member toward the transmitting portion;
The elastic part is composed of the biasing member,
The robot finger unit according to any one of claims 1 to 4, wherein the robot finger unit is provided. The first rocking member has an elastic deformation portion that is more easily elastically deformed than other portions of the first rocking member.
The robot finger unit according to any one of claims 1 to 6, wherein the robot finger unit is configured as described above. The elastically deforming portion is disposed between the first fulcrum and the transmitting portion in the first swing member.
The robot finger unit according to claim 7. The robot finger unit according to claim 1 is provided.
Robot hand characterized by that. The robot finger unit according to claim 1 is provided.
A robot characterized by that.

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