Power tool changer

Abstract

A tool changer is described comprising a robot side portion having a longitudinal axis and intended to be fixed to a manipulator, and a tool side portion intended to be fixed to a tool and to abut against the robot side portion along said longitudinal axis. The tool changer further comprises a locking mechanism for locking the tool side portion on the robot side portion, and an actuator of the locking mechanism. The locking mechanism is selectively movable by the actuator between a locked position, in which they engage with the tool side portion abutting against the robot side portion, preventing the two portions of the tool changer from being separated, and an unlocked position, in which they do not engage with the tool side portion, so that the tool side portion can be separated from the robot side portion. The actuator of the locking device is an electric motor whose drive shaft rotates on a rotation axis parallel to the longitudinal axis and is not orthogonal or skewed with respect to the longitudinal axis.

Description

Technical Field

[0001] The present invention relates to a power tool changer, particularly a tool changer for EOAT (End-of-Arm Tool) applications, which allows tools to be detachably attached to a robot manipulator. Background Technology

[0002] In the field of industrial automation, it is known to use tool changing devices or, more simply, tool changers that allow a robot's manipulator (e.g., an articulated arm) to pick up and move tools each time as required for a given mechanical operation.

[0003] The present invention particularly relates to a tool changer comprising:

[0004] - The so-called tool side section, which is designed to be fixed to the tool to be picked up and moved; and

[0005] - The so-called robot side section is designed to be fixed to the manipulator for movement integrally with the manipulator and is designed to receive and hold the tool side section for the required time.

[0006] An example of such an electric tool changer is described in document DE 102016222506 under the name of the applicant.

[0007] In this type of tool changer, a component for reversibly locking the tool-side portion is housed in the robot-side portion. Tool changers in which the locking component moves at high speed to quickly (e.g., in less than 1 second) engage and disengage the tool-side portion are conventionally called "quick changers".

[0008] For example, the German company SCHUNK GmbH & Co KG sells an electric tool changer under the trade name 'Electric Tool Changer EWS', which is described in detail in the specifications.

[0009] Other examples of power tool changers are described in ATI Industrial Automation documents US 8132816, US 8209840, US 8747288, and US 2012 / 0277080. In particular, US 8132816 describes a tool changer characterized in that the axis of rotation of the shaft of the electric motor acting as the actuator is orthogonal to the connection direction of the tool-side portion and the robot-side portion, i.e., the direction in which one portion is inserted into the other.

[0010] In one of the most common configurations, the locking mechanism consists of metal balls housed in the robot's side section, which can selectively move between the following positions:

[0011] - Locking position, wherein the metal ball engages with a corresponding seat or groove on the tool side portion to prevent the tool side portion from slipping out; and

[0012] - Idle position, in which the metal ball does not engage with the tool side portion, so the tool side portion is not held and can be separated from the robot side portion.

[0013] In practice, these balls are housed in dedicated receptacles in the robot side section and can move between a retracted position (idle position) and a protruding position (locked position). In the retracted position, the balls do not protrude from their respective receptacles or only partially protrude from their respective receptacles. In the protruding position, the balls protrude from their respective receptacles just enough to engage with the tool side section and define a shape connection with the tool side section, much like an interlocking / relief.

[0014] The ball can be moved using an actuator, which is currently electric.

[0015] The applicant has found that solutions with orthogonal axes, such as those described in US 8132816, are often subject to the following drawbacks: the electric motor protrudes laterally from the tool changer, and it is generally difficult to manufacture a tool changer with orthogonal axes that has a minimum lateral dimension, which is the minimum lateral dimension in the direction transverse to the connection direction of the convex and concave portions. This can cause operational problems when the tool and actuator operate in confined spaces, such as in a mold. In these cases, it is desirable that the operation of the actuator is not limited by the size of the tool changer. Summary of the Invention

[0016] Therefore, the object of the present invention is to provide a power tool changer that is particularly compact while having the same performance as conventional solutions.

[0017] Therefore, the present invention relates to a power tool changer according to claim 1.

[0018] In particular, the present invention relates to a tool changer comprising:

[0019] - Defined as the first part of the robot's side section, which has a longitudinal axis and is intended to be fixed to the manipulator;

[0020] - Defined as the second part of the tool-side portion, which is intended to be fixed to the tool and abut against the robot-side portion along the longitudinal axis, thus the longitudinal axis is the axis along which the two portions are joined;

[0021] - A locking mechanism for locking the tool side portion onto the robot side portion, and an actuator for the locking mechanism.

[0022] The locking mechanism can be selectively moved between a locked position and an unlocked position by an actuator. In the locked position, the locking mechanism engages with the tool-side portion that abuts the robot-side portion, thereby preventing the two parts of the tool changer from separating. In the unlocked position, the locking mechanism does not engage with the tool-side portion, thereby allowing the tool-side portion to separate from the robot-side portion.

[0023] The actuator of the locking device is an electric motor, whose drive shaft rotates about a rotation axis that is parallel to the longitudinal axis and is neither orthogonal nor skewed relative to the longitudinal axis.

[0024] Compared to schemes with orthogonal or skewed axes, this configuration provides the same performance despite resulting in a smaller overall size: the electric motor can be located side by side with the locking mechanism on the right side of the locking mechanism and extends parallel to the longitudinal axis, while occupying less space in the lateral direction since the main size of the motor is length.

[0025] Preferably, the locking mechanism comprises a plurality of balls received in respective receptacles on the robot-side portion. The balls act as retaining elements: in the locked position, the balls protrude at least partially from their respective receptacles and engage with slots or corresponding niches formed by recesses on the tool-side portion fitted onto the robot-side portion; conversely, in the unlocked position, the balls do not protrude from their respective receptacles and do not engage with slots or niches on the tool-side portion. In practice, the balls can abut / restrict the tool-side portion to lock it onto the robot-side portion and can be released to allow the tool-side portion to be released.

[0026] In a preferred embodiment, the balls are radially movable relative to the longitudinal axis within the respective receptacle. Preferably, depending on the number of balls, they are arranged at regular intervals around the longitudinal axis, for example, spaced apart at central angles of 120°, 90°, 45°, etc.

[0027] Preferably, the locking mechanism includes a ring-shaped control element disposed on the robot side portion at a position radially outward of the ball and movable between a first position and a second position under the action of an electric motor. In the first position, the ring-shaped control element presses the ball into a locked position, and in the second position, the ball is in an unlocked position. In effect, the movement of the ring-shaped control element is driven by the electric motor, and the movement of the ring-shaped control element determines the position of the ball.

[0028] More preferably, the sphere's reservoir is a radial through-hole located on the element or wall of the robot's side portion, and the annular control element includes a circular portion surrounding these reservoirs, the circular portion being provided with:

[0029] - A recess, in the unlocked position, which accommodates the ball; and

[0030] - A step or ramp, in the locked position, against which the ball rests. In fact, the step or ramp is radially more inward relative to the recess.

[0031] Two embodiments are possible. In the first embodiment, each step or ramp extends on a plane that is not orthogonal to the radial direction. In this embodiment, the step or ramp forms an angle other than 90°. On the other hand, in the second embodiment, each step or ramp extends on a plane orthogonal to the radial direction.

[0032] Preferably, the ring-shaped control element is mounted on the robot side portion and is rotatable relative to the robot side portion about a longitudinal axis between the following positions:

[0033] - Corresponding to the first angular position of the locking position, in which the ball abuts against the step or ramp, and the step or ramp is aligned with the ball's seat, and simultaneously, the recess is not angularly aligned with the ball's seat; and

[0034] - A second angular position corresponding to the unlock position, in which the ball is at least partially received in the recess of the annular control element, the recess being aligned with the ball's seat, and the step or ramp being angularly misaligned relative to the ball's seat.

[0035] In this configuration, an electric motor causes a ring-shaped control element to rotate alternately by an angle α in two directions to lock / unlock the tool-side portion. This angle is equal to a central angle defined between the recess and the stepped / climbed portion, the center of which lies on the longitudinal axis.

[0036] In a preferred embodiment, the robot-side portion includes a cup-shaped element into which a convex portion of the tool-side portion is inserted. The ball's reservoir is a hole radially penetrating the sidewall of the cup-shaped element. An annular control element is slidably mounted on the cup-shaped element and prevents the ball from falling outward from its reservoir. Alternatively, the ball is prevented from falling inward by creating a tapered reservoir (i.e., narrower at its closest point to the longitudinal axis) that allows just enough space for a portion of the ball to protrude (in the locked position).

[0037] Preferably, the ring control element includes a protrusion or lever connected to the electric motor by means of an eccentric connection.

[0038] Preferably, the tool changer includes a transmission mechanism that, in response to rotation applied in both directions by the drive shaft of the electric motor, causes the ring control element to rotate about a longitudinal axis in both directions. Therefore, in this embodiment, the electric motor and the ring control element are not directly coupled but are actually coupled via the transmission mechanism.

[0039] The transmission mechanism includes a thrust element functionally inserted between an electric motor and a ring control element. The thrust element is eccentrically rotatable about the axis of rotation of the electric motor's drive shaft; that is, it follows an arcuate trajectory and applies torque to the ring control element in response to rotation exerted by the drive shaft itself. This torque causes the ring control element to slide rotationally on the robot-side portion.

[0040] The eccentric connection between the locking mechanism and the electric motor ensures that the locked position remains stable even when the electric motor is off, such as in the event of a power outage.

[0041] Preferably, the transmission mechanism further includes a gear inserted between the thrust element and the drive shaft of the electric motor and defining a desired transmission ratio between these components.

[0042] Preferably, the ring control element is slightly flexible to compensate for gaps between the components of the tool changer due to manufacturing tolerances.

[0043] Preferably, the tool changer includes an electrical connection device for connecting power lines reaching the robot-side portion to corresponding power lines on the tool-side portion to precisely power the tool. More preferably, the device includes two connectors, one for each of the two portions of the tool changer, mounted coaxially along a longitudinal axis; this allows cables to pass substantially along the longitudinal axis of the tool changer, rather than on the outside, where such cables could pose a hazard to operators working near the robot. The two connectors are functionally connected to maintain power line continuity by connecting the tool-side portion to the robot-side portion, or conversely, the connectors separate when the two portions of the tool changer are separated. Attached Figure Description

[0044] Other features and advantages of the invention will become more apparent from the following description of preferred, but not exclusive, embodiments, illustrated with reference to the accompanying drawings. This description of preferred embodiments is for illustrative purposes only and not for limiting purposes, wherein:

[0045] - Figure 1 This is a perspective view of a tool changer according to the present invention, wherein the robot-side portion is separated from the tool-side portion;

[0046] - Figure 2 yes Figure 1 The tool changer shown is a perspective view, in which the robot-side portion is connected to the tool-side portion;

[0047] - Figure 3 yes Figure 1An exploded view of only the robot side of the tool changer shown;

[0048] - Figure 4 yes Figure 1 A longitudinal sectional view of the robot side portion of the tool changer shown;

[0049] Figure 5 is Figure 1 The tool changer shown is a cross-sectional view of the robot side portion in the first configuration;

[0050] Figure 6 is Figure 1 A cross-sectional view of the tool changer in the second configuration on the robot side;

[0051] - Figure 7 yes Figure 1 The tool changer shown is a perspective view, in which the robot-side portion is separated from the tool-side portion and accessories;

[0052] - Figure 8 yes Figure 1 The tool changer shown is a perspective view and a partial longitudinal sectional view, in which the robot-side portion is connected to the tool-side portion, and in which the attachments are assembled;

[0053] - Figure 9 is a cross-sectional view of the robot side portion of the tool changer according to a second embodiment of the tool changer according to the invention, in the first configuration;

[0054] - Figure 10 is a cross-sectional view of the robot side portion in the second configuration of a second embodiment of the tool changer according to the present invention;

[0055] - Figure 11 This is an enlarged view of a portion of Figure 9. Detailed Implementation

[0056] Referring to all the accompanying drawings, reference numeral 100 indicates a tool changer according to the invention, comprising a robot-side portion 1 and a tool-side portion 2. The robot-side portion 1 is intended to be attached to an industrial manipulator, such as a robotic arm, and the tool-side portion 2 is intended to be attached to a tool that must be interchangeably mounted on the manipulator, such as a gripper, clamping element, pliers, suction cup, or generally any tool available in the field of industrial automation EOAT.

[0057] The reference numeral ZZ denotes the connecting axis of parts 1 and 2, hereinafter referred to as the longitudinal axis, that is, the axis along which the tool-side part 2 is at least partially inserted into the robot-side part 1. Specifically, Figure 1 The diagram shows two parts, 1 and 2, separated from each other, so that they can move closer or further apart, for example. Figure 2 The diagram shows two parts 1 and 2 that are functionally connected to each other, corresponding to a configuration in which tools are mounted on manipulators and ready for use.

[0058] The tool-side portion 2 is provided with a convex portion 3, which can be inserted into a corresponding first compartment 4 of the robot-side portion, preferably a through compartment. Preferably, the convex portion 3 and the first compartment 4 have complementary shapes; in the example shown in the figure, the convex portion and the first compartment are circular.

[0059] Preferably, as shown in the figure, the tool side portion 2 extends around the second compartment 4', that is, the tool side portion is substantially annular.

[0060] The robot side portion 1 is provided with a plurality of balls 5, which are received in corresponding seats and are movable between a retracted position and an extended position. In the retracted position, the balls 5 do not protrude from their respective seats, and in the extended position, the balls 5 protrude at least partially from their respective seats. The tool side portion 2 includes a groove, hole, or niche 6' provided on the convex portion 3 for receiving the balls 5; when the balls 5 are in the extended position, a portion of the balls is received in the niche 6' located on the tool side portion 2, thereby preventing the two portions 1 and 2 from separating and instead locking the tool side portion 2 onto the robot side portion 1.

[0061] An alignment mechanism is present on the robot-side portion 1. This mechanism functions to assist in the proper alignment of portions 1 and 2 when they are close to each other, and to ensure that the receiving niche 6′ on the tool-side portion 2 is aligned with the corresponding ball 5. In the example shown in the figures, the alignment mechanism includes two locating pins 7 cantilevered from the robot-side portion 1, particularly from the first compartment 4, and two corresponding holes or recesses in the tool-side portion 2. The two locating pins 7 define the alignment direction in the radial direction relative to the ZZ axis and in the angular direction between the ball 5 and the receiving niche 6′.

[0062] The embodiment shown in the figure is equipped with a pneumatic connection device, but generally, the tool changer according to the invention can be manufactured regardless of the presence of this feature. The pneumatic connection device is used to supply compressed air (or vacuum) to the tool combined with part 2 by using a passage / pipe within the tool changer 100 instead of an external pipe.

[0063] In the example shown in the accompanying drawings, the tool-side portion 2 has a fitting 8 on its side for inserting a delivery line for supplying compressed air to the tool. The fitting 8 connects to a nozzle (not visible) located in the convex portion 3 via a channel within the tool-side portion 2. The nozzle of the tool-side portion 2 is received in a corresponding nozzle 9 of the robot-side portion 1, forming a fluid-impermeable connection between the nozzles of the tool-side portion and the corresponding nozzles of the robot-side portion. The nozzle 9 is in turn connected via an internal passage / pipe to a fitting 10 located on the side of the robot-side portion 1. Therefore, ultimately, when the two portions 1 and 2 are connected to each other, the fitting 8 of the tool-side portion 2 is in fluid connection with the corresponding fitting 10 of the robot-side portion 1.

[0064] Special reference Figure 3 The robot side portion 1 includes a body 11 in which components are housed. A cup-shaped element 12 is housed in a first compartment 4, and a seat 6 for a ball 5 is located on the cup-shaped element. The seat 6 is a radial through-hole obtained through the sidewall of the cup-shaped element 12, i.e., a hole facing the longitudinal axis ZZ. A collar 13, functioning as a housing or cover, can be positioned on the cup-shaped element 12 to cover the edge. Reference numeral 9' indicates an O-ring seal for a nozzle 9 arranged circumferentially in the cup-shaped element 12.

[0065] Clearly, when the tool side portion 2 is correctly inserted into the first compartment 4 of the robot side portion 1, the seat 6 and the niche portion 6′ face each other and are aligned in the radial direction.

[0066] Reference numeral 14 indicates a ring-shaped control element, which functions as follows: to push the ball 5 into the corresponding niche 6′ to lock the tool-side portion 2 onto the robot-side portion 1. The ring-shaped control element 14 is rotatable in two directions on a plane orthogonal to the longitudinal axis ZZ, which is actually the upper surface of the cup-shaped element 12.

[0067] The ring control element 14 is driven by an electric motor 16, which is housed in the body 11 and arranged such that its drive shaft 17 is parallel to the longitudinal axis ZZ. In other words, the axis of rotation of the drive shaft 17 of the electric motor 16 is parallel to the longitudinal axis ZZ of the tool-side portion 2 along its insertion into the robot-side portion 1. Reference numeral 18 generally indicates gears, which are cascaded to define the desired gear ratio; gear 18 is functionally connected to the drive shaft 17 of the electric motor 16 and the thrust element 22. Gear 18 is enclosed in a housing defined by two stops 19 and 20, which are screwed to the body 11, and the electric motor 16 is secured to the stops from below by screws. The rotation applied to the gear 18 by the electric motor 16 is applied to the thrust element 22, which is eccentrically mounted on the gear 23, particularly in the bore 24.

[0068] Therefore, gear 18 actually defines the transmission system, but importantly, the rotation applied by electric motor 16 causes thrust element 22 to rotate about an axis parallel to the longitudinal axis ZZ, so that the thrust element follows a circular path.

[0069] Able to observe Figure 4 To make this aspect easier to understand, Figure 4 A longitudinal section of the robot side portion 1, considered in a vertical plane containing axis ZZ, is shown: the axis of rotation of the drive shaft 17 of the electric motor 16 is indicated by 26, the axis of rotation of the gear 23 is indicated by 27, and the geometric axis of the thrust element 22 is indicated by 28. The geometric axis 28 rotates about axis 27; that is, the thrust element 22 remains parallel to the longitudinal axis ZZ but rotates about the center of rotation of the gear 23, which is eccentrically coupled thereto, as defined / defined in this patent application. Essentially, an arm is provided between the geometric axis of the thrust element 22 and the axis of rotation 26 of the electric motor 16.

[0070] Thanks to the eccentric connection just described, the tool changer 100 is irreversible, meaning that even if the electric motor 16 stops operating due to a malfunction or power outage, the ring control element 14 will not rotate into the unlocked position due to the ball 5. This ensures that the tool-side portion 2 will not unintentionally disengage from the robot-side portion 1, thereby improving safety.

[0071] Reference numeral 25 indicates the electronic control card for the electric motor 16. The electric motor can operate in two directions of rotation, or it can always rotate in the same direction: for example, rotating 200° to lock and selecting 160° to unlock.

[0072] Preferably, as shown in the accompanying drawings, the thrust element 22 is equipped with a pin on which the idler roller 26 is mounted. Therefore, the roller 26 can rotate both about the geometric axis 28 of the thrust element and about the rotation axis 27 of the gear 23.

[0073] The ring control element 14 includes a generally circular portion 14′ and a protruding portion 14″ that can also be defined as a lever and is integral with the circular portion 14′.

[0074] The circular portion 14′ further includes:

[0075] - When the tool side part 2 must be inserted into the robot side part 1 or must be separated from the robot side part 1, that is, when the robot side part 1 is in the unlocked configuration / position, the ball 5 is accommodated in the recess 29 therein;

[0076] - The stepped portion 30 adjacent to the recess 29, i.e., the inclined and tapering surface, functions to at least partially push the ball 5 away from its corresponding receiving seat 6, so that the robot-side portion enters a locking configuration / position in which the tool-side portion 2 cannot be separated / disassembled. The stepped portion 30 is radially closer to the inner circumference of the annular control element 14 than the recess 29. Figure 1-8 In the example shown, each step 30 extends on an inclined plane that is not orthogonal to the radial direction.

[0077] In the case where the protrusion 14″ defines the guide 31 into which the thrust element 22 is inserted, the protrusion 14″ is hollow and fitted onto the thrust element 22. In an alternative embodiment not shown in the figures, the protrusion 14″ is solid and the thrust element 22 pivots thereon.

[0078] In Figure 5, the robot side portion 1 is shown in the unlocked configuration / position, where the ball 5 is received in the corresponding seat 6 of the cup-shaped element 12 and held therein by the annular control element 14. The ball 5 will not fall off the cup-shaped element 12 because it is held from the outside by the annular control element 14.

[0079] Figure 6 shows the robot side portion 1 in a locked configuration / position, where the ball 5 protrudes partially inward from the corresponding reservoir 6, i.e., protrudes towards the longitudinal axis ZZ, due to the thrust applied by the stepped portion 30 of the annular control element 14. Since the reservoirs 6 are slightly tapered, i.e., they narrow towards the axis ZZ, the ball 5 will not fall into the interior of the cup-shaped element 12. Therefore, the ball 5 can only protrude as much as shown in Figure 6, and cannot protrude further.

[0080] The ball 5, the corresponding niche 6' on the tool side part 2, the ring control element 14 and the thrust element 22 together define a locking mechanism for locking the tool side part 2 onto the robot side part 1. The electric motor 16 can activate the locking mechanism and deactivate the locking mechanism so as to lock the two parts 1 and 2 together or to separate / disassemble part 2.

[0081] The operation of the tool changer 100 can be understood by comparing Figures 5 and 6.

[0082] Starting from the unlocked position shown in Figure 5, the electric motor 16 is activated, i.e., the corresponding drive shaft 17 rotates. The gear cascade 18 transmits rotation to the gear 23 according to the transmission ratio defined by the ratio of the number of teeth of the gears. The gear 23 then transmits rotation to the thrust element 22 pivoting thereon. Since the thrust element 22 engages with the guide 31 located in the protrusion 14″ of the annular control element 14, during rotation, the thrust element 22 applies thrust to the protrusion 14″, thereby causing the entire annular control element 14 to rotate about the longitudinal axis ZZ.

[0083] In the examples shown in Figures 5 and 6, the ring control element 14 has been rotated by an angle α; in other words, the angle α corresponds to the rotation applied to the ring control element 14 to guide the tool changer 100 from the locked position to the unlocked position by applying rotation in the opposite direction, or vice versa.

[0084] By observing Figure 6, it can be noted that the recess 29 is no longer aligned with the ball 5, but is offset upward at an angle equal to angle α; the ball 5 rests against the step 30, so the step 30 and the corresponding recess 29 define a central angle equal to α.

[0085] Preferably, the guide 31 has a recess 32 that defines a stable position for the thrust element 22. The recess helps prevent the robot side portion 1 from accidentally switching to the unlocked configuration, for example, due to a power outage, when the electric motor 16 is not powered on.

[0086] In the example shown in the figure, the interaction between the thrust element 22 and the guide 31 is facilitated by the rotation of the roller 26.

[0087] When the ball 5 protrudes from its seat 6 toward the longitudinal axis ZZ and the tool side portion 2 is inserted into the first compartment 4, the protruding portion of the ball 5 is inserted into the niche portion 6′ existing on the convex portion 3 of the tool side portion 2.

[0088] Advantageously, as can be seen from the figures, by arranging the electric motor 16 such that the corresponding rotation axis 26 is parallel to the longitudinal axis ZZ, the overall size of the tool changer 100 can be precisely minimized in the longitudinal direction. As a result, the tool changer 100 is extremely compact, yet its performance is the same as that of a tool changer with orthogonal axes (i.e., with an electric motor whose rotation axis is orthogonal to the longitudinal axis).

[0089] For example, the ring control element 14 can be obtained from a metal sheet by machining or by laser cutting.

[0090] Preferably, the ring control element 14 is slightly flexible, that is, it allows for the automatic recovery of any possible gaps between parts caused by manufacturing tolerances and also allows for the application of preload on the thrust element 22.

[0091] Figure 7 and Figure 8 A tool changer 100 equipped with an electrical connection device 33 is shown, which includes a first connector 34 that can be fixed to a first compartment 4 of a robot-side portion 1 and a second connector 35 that can be fixed to a second compartment 4' of a tool-side portion 2. Connectors 34 and 35 can be fixed to the corresponding portions 1 and 2 of the tool changer 100 by means of screws 36.

[0092] Power lines 37′ converge to the first connector 34, and power lines 37″ converge to the second connector and must each be connected to the corresponding power line 37′. For this purpose, the second connector 35 is provided with connector plugs 38, each of which is connected to line 37″, and the first connector 34 is provided with corresponding connector plugs 39.

[0093] Since connectors 34 and 35 are coaxial, i.e., arranged along the longitudinal axis ZZ, when the tool-side portion 2 is inserted into the compartment 4 of the robot-side portion 1, the two connectors 34 and 35 are functionally connected, i.e., plugs 38 and 39 are electrically connected to make the power lines 37′ and 37″ continuous. When the tool-side portion 2 is separated from the robot-side portion 1, connectors 34 and 35 also separate.

[0094] Advantageously, device 33 allows power lines 37′ and 37″ to be positioned through compartment 4. This allows power to be supplied directly to the tool from the center of the robot wrist on which the tool changer 100 is mounted using power line 37′, thus avoiding the movement of power lines (power cables) around the robot during tool changer rotation. In other words, thanks to this arrangement, bulky and dangerous power lines around the tool are avoided, thereby improving the safety of personnel working near the tool itself.

[0095] As an alternative to the configuration just described, device 33 also allows power lines 37′, 37″ to pass through windows 40 radially opened in compartment 4. Figure 3 ).

[0096] Preferably, one or more power lines 37′ and / or 37″ include spring-loaded contact probes.

[0097] Figures 9-11 show a second embodiment 101 of the tool changer according to the invention, which differs from the first embodiment 100 only in the shape of the annular control element 14, which will be explained below.

[0098] Specifically, Figure 9 is a plan view of the robot side portion 1 in the locked configuration, i.e., where the ball 5 protrudes from the corresponding seat 6 toward the longitudinal axis ZZ portion (through the center of the compartment 4), while Figure 10 is a plan view of the robot side portion 1 in the unlocked configuration, i.e., where the ball 5 is completely contained in the corresponding seat 6 provided on the cup-shaped element 12.

[0099] Figure 11 This is an enlarged view of a portion of Figure 9, showing sphere 5.

[0100] Referring to Figures 9-11, in this embodiment, the stepped portion 30′ adjacent to the recess 29 provided on the annular control element 14 is tangent to the radial direction (dashed line R) (plane T), that is, each of the stepped portions 30′ extends in a plane orthogonal to the diameter of the compartment 4 passing through the longitudinal axis ZZ, as best shown in Figures 9 and 11. This configuration involves the absence of a location in the annular control element 14 where a torque capable of causing rotation of the annular control element would be generated; the reason is simple: the ball 5 can only transmit thrust in the radial direction, and since the stepped portion 30′ is orthogonal to this direction, no non-radial thrust is generated on the annular control element 14. As a result, the annular control element 14 will not accidentally rotate and release the tool side portion 2.

Claims

1. A tool changer (100, 101), comprising: - Robot side section (1), which has a longitudinal axis (ZZ) and is designed to be fixed to the manipulator; - Tool side portion (2), which is intended to be fixed to the tool and abut against the robot side portion (1) along the longitudinal axis (ZZ); - A locking mechanism (5) for locking the tool-side portion (2) onto the robot-side portion (1); and -Actuator of locking mechanism (5), The locking mechanism (5, 14) is selectively movable between a locked position and an unlocked position. In the locked position, the locking mechanism engages with the tool-side portion (2) abutting the robot-side portion (1), thereby preventing separation from the robot-side portion (1). In the unlocked position, the locking mechanism does not engage with the tool-side portion (2), thereby allowing the tool-side portion to be detached from the robot-side portion (1). The characteristic feature is that the actuator of the locking mechanism (5, 14) is an electric motor (16) with a drive shaft (17) that rotates about a rotation axis (26) parallel to the longitudinal axis (ZZ); The locking mechanism (5, 14) includes a plurality of balls (5) which are received in corresponding seats (6) provided on the robot side portion (1), wherein, in the locked position, the balls (5) protrude at least partially from their respective seats (6) and engage with slots or corresponding niches (6′) provided on the tool side portion (2) fitted on the robot side portion (1) and thus forming recesses, and in the unlocked position, the balls (5) do not protrude from their respective seats (6) and do not engage with the slots or niches (6′) on the tool side portion (2); The locking mechanism (5, 14) includes a ring control element (14) arranged radially outward on the robot side portion (1) and movable between a first position and a second position under the action of the electric motor (16). In the first position, the ring control element presses the ball (5) into the locked position, and in the second position, the ball (5) is in the unlocked position. The ring control element (14) includes a protrusion or lever (14′′) connected to the electric motor (16) by means of an eccentric connection. The eccentric connection is configured such that the ring control element remains in the locked position when the electric motor is de-energized.

2. The tool changer (100, 101) according to claim 1, wherein, The ball (5) can move radially relative to the longitudinal axis (ZZ).

3. The tool changer (100, 101) according to claim 1, wherein, The cradle (5) of the ball (5) is a radial through hole on the element (12) of the robot side portion (1), and the annular control element (14) includes a circular portion (14') surrounding these cradles (6), which is provided with: - A recess (29), in the unlocked position, which accommodates the ball (5); and - Step or ramp (30, 30′), in the locked position, the ball (5) abuts against the step or ramp.

4. The tool changer (100, 101) according to claim 3, wherein: - Each of the aforementioned steps or ramps (30) extends in a plane that is not orthogonal to the radial direction (R); or - Each of the aforementioned steps or ramps (30′) extends in a plane (T) orthogonal to the radial direction (R).

5. The tool changer (100, 101) according to claim 3 or 4, wherein, The annular control element (14) is mounted on the robot side portion (1) and is rotatable relative to the robot side portion about the longitudinal axis (ZZ) between the following positions: - Corresponding to the first angular position of the locking position, in the first angular position, the ball (5) abuts against the step or the inclined surface (30, 30′) and the step or the inclined surface is aligned with the seat (6) of the ball (5), and the recess (29) is not aligned angularly with respect to the seat (6) of the ball (5); and - A second angular position corresponding to the unlock position, in which the ball (5) is at least partially accommodated in the recess (29) of the annular control element (14), the recess being aligned with the seat (6) of the ball (5), and the step portion or the ramp (30, 30′) being angularly misaligned with the seat (6) of the ball (5).

6. The tool changer (100, 101) according to claim 5, wherein, The electric motor (16) causes the annular control element (14) to rotate alternately by an angle (α) in two directions to lock / unlock the tool side portion (2), the angle being equal to the central angle defined by the recess (29) and the step portion or the inclined surface (30, 30′), the center of which is located on the longitudinal axis (ZZ).

7. The tool changer (100, 101) according to any one of claims 1-6, wherein, The robot side portion (1) includes a cup-shaped element (12), and the convex portion (3) of the tool side portion (2) is inserted into the cup-shaped element. The receiving seat (6) of the ball (5) is a hole provided radially through the side wall of the cup-shaped element. The annular control element (14) is slidably mounted on the cup-shaped element (12) and prevents the ball (5) from falling outward from its corresponding receiving seat (6).

8. The tool changer (100, 101) according to any one of claims 1 to 7, comprising a transmission mechanism (18, 22) that, in response to rotation applied in both directions by the drive shaft (17) of the electric motor (16), causes the annular control element (14) to rotate about the longitudinal axis (ZZ) in both directions.

9. The tool changer (100, 101) according to claim 8, wherein, The transmission mechanism includes a thrust element (22) functionally inserted between the electric motor (16) and the annular control element (14), wherein the thrust element (22) is eccentrically rotated about the rotation axis (26) of the drive shaft (17) of the electric motor (16) in response to rotation applied by the drive shaft (17) itself and applies torque to the annular control element (14).

10. The tool changer (100, 101) according to claim 9, wherein, The transmission mechanism also includes a gear (18) inserted between the thrust element (22) and the drive shaft (17) of the electric motor (16) to define the transmission ratio between these components.

11. The tool changer (100, 101) according to any one of claims 1-10, wherein, The ring control element (14) has a small amount of elasticity to compensate for the gaps between the components of the tool changer due to manufacturing tolerances.

12. The tool changer (100, 101) according to any one of claims 1-11, wherein, Even when the electric motor (16) is turned off, the locking position of the locking mechanism (5, 14) remains stable.

13. The tool changer (100, 101) according to any one of claims 1-12, comprising an electrical connection device (33) having a first connector (34) mountable on the robot side portion (1) and a second connector (35) mountable on the tool side portion (2). in, Each of the first connector (34) and the second connector (35) supports at least one power line (37′, 37′′) and is functionally connected to connect the respective power lines (37′, 37′′) to each other and can be disconnected to disconnect the power lines (37′, 37′′). The first connector (34) and the second connector (35) are installed at the longitudinal axis (ZZ).

14. The tool changer (100, 101) according to any one of claims 1-12, comprising an electrical connection device (33) having a first connector (34) mountable on the robot side portion (1) and a second connector (35) mountable on the tool side portion (2). in, The connectors (34, 25) support the corresponding power lines (37′, 37′′) and can be connected / disconnected together with the robot-side portion (1) and the tool-side portion (2). Wherein, the robot side portion (1) extends coaxially with the longitudinal axis (ZZ) around the first compartment (4) and the first connector (34) can be installed in the first compartment (4), and / or The tool side portion (2) extends coaxially with the longitudinal axis (ZZ) around the second compartment (4′) and the second connector (35) can be installed in the second compartment (4′).

15. The tool changer (100, 101) according to any one of claims 13-14, wherein, The power lines (37, 37′′) connected by means of the electrical connection device (33) pass through the two parts (1, 2) of the tool changer substantially along the longitudinal axis (ZZ).

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