Element changer

Abstract

Element changer that features: a first plate (1) designed to be attached to a first element (8); a second plate (2) designed to be attached to a second element (5), wherein the second plate (2) includes a tubular wall section (10) extending from an outer peripheral edge section of the second plate (2) in its axial direction; a housing (3) designed to be attached to the first element (8) via the first plate (1), wherein the housing (3) has a diameter smaller than that of the second plate (2); several actuating pin elements (4) which are inserted into the housing (3), each of the pin elements (4) having a wedge surface (12c) on one side near the first plate (1); and a preloading means (13) provided in the housing (3), wherein the preloading means (13) is designed to preload the actuating pin elements (4) outwards in a radial direction of the housing (3), where: an engagement section (10a) is provided at a front end section of the tubular wall section (10) in its axial direction, wherein the engagement section (10a) projects inwards in a radial direction of the tubular wall section (10); and when the actuating pin elements (4) are pushed into the housing (3) against a preload force of the preloading device (13), each wedge surface (12c) is disengaged from the engagement section (10a) so that the second element (5) can be removed from the first element (8).

Description

Technical area

[0001] The present invention relates to an element changer for changing an element such as a machine tool, a clamp, a pallet, a jig, and an object to be subjected to a machining process by attaching / detaching the element to / from another element such as a robot arm, a movable portion of a conveyor machine, and a table serving as a stationary stand. background

[0002] Known examples of such an element changer include a device described in Patent Literature 1 below. The known device is constructed as follows.

[0003] The tool changer described in Patent Literature 1 is used to change a tool such as a jig, a machine tool, and a clamp by manually attaching / detaching the tool to / from a handling main body mechanism such as a jig station and a robot arm. The tool changer includes: an L-shaped connector with a semicircular engagement recess; and a camshaft with an engagement cam configured to engage the engagement recess. The camshaft is rotated by rotating a handle attached to one end of the camshaft. The rotation of the camshaft causes the engagement cam to engage / disengage from the engagement recess. Citation listPatent literature

[0004] Patent Literature 1: Unexamined Japanese Patent Publication No. 2008-272875 Overview of the inventionTechnical problem

[0005] The device described in Patent Literature 1 has the following disadvantages.

[0006] The handle for rotating the camshaft is required for the tool changer described in Patent Document 1. If the handle is always attached to the camshaft, it may interfere with the operation of, for example, a tool attached to the handling main body mechanism. If the handle is removed from the camshaft after use and used only when changing a tool, it is necessary to properly store the unused handle.

[0007] An object of the present invention is to provide an element changer configured to change an element without using a handle. Solution to the problem

[0008] To achieve the above object, in one aspect of the present invention, an element changer is constructed as follows, for example, as shown in Fig. 1A to Fig. 6 shown.

[0009] An element changer of this aspect includes: a first plate 1 configured to be attached to a first element 8; a second plate 2 configured to be attached to a second element 5, the second plate 2 including a tubular wall portion 10 extending from an outer peripheral edge portion of the second plate 2 in its axial direction; a housing 3 configured to be attached to the first element 8 via the first plate 1, the housing 3 having a diameter smaller than that of the second plate 2; a plurality of actuating pin elements 4 inserted into the housing 3, each of the pin elements 4 having a wedge surface 12c on a side near the first plate 1;and a biasing means 13 provided in the housing 3, the biasing means 13 being configured to bias the actuating pin members 4 outward in a radial direction of the housing 3. An engaging portion 10a is provided at a front end portion of the tubular wall portion 10 in its axial direction, and the engaging portion 10a protrudes inward in a radial direction of the tubular wall portion 10. When the actuating pin members 4 are pushed into the housing 3 against a biasing force of the biasing means 13, each wedge surface 12c is disengaged from the engaging portion 10a to allow the second member 5 to be detached from the first member 8.

[0010] The element changer of this aspect described above offers the following functions and effects.

[0011] The second element is removed by inserting the actuating pin elements into the housing. This makes it possible to change the second element without using a handle.

[0012] The element changer of the above aspect may be arranged so that: as for example in Fig. 5A and Fig. 5B, a projection 20 is provided at a central portion of the housing 3; a recess 6b into which the projection 20 is to be fitted is provided at a central portion of the second plate 2; and a positioning pin 22 adapted to be fitted into a pin hole 21 of the second plate 2 is provided so as to protrude from the housing 3, the pin hole 21 being provided at a portion of the second plate 2 other than its central portion.

[0013] With this arrangement, the position of the second plate in the circumferential direction relative to the housing is always the same. Consequently, the position of the second element relative to the first element, to which the second element is attached via the element changer, is determined relative to the circumferential direction.

[0014] Furthermore, the element changer of the above aspect may be arranged as follows. A front end portion 23 of the positioning pin 22 has a shape such that: the front end portion 23, when fitted into the pin hole 21, contacts an inner wall surface of the pin hole 21 in a circumferential direction of the second plate 2; and one or more gaps are created between the front end portion 23 and the inner wall surface of the pin hole 21 in a radial direction of the second plate 2.

[0015] This arrangement improves the accuracy of the position of a tool in the circumferential direction relative to the first element to which the tool is attached via the element changer.

[0016] In a further aspect of the invention, an element changer, such as that used in Fig. 7A to Fig. 11B is shown.

[0017] An element changer of this aspect includes: a first plate 1 configured to be attached to a first element 8, the first plate 1 including a tubular wall portion 10 extending from an outer peripheral edge portion of the first plate 1 in its axial direction; a second plate 2 configured to be attached to a second element 5; a housing 3 configured to be attached to the second element 5 via the second plate 2, the housing 3 having a diameter smaller than that of the first plate 1; a plurality of actuating pin elements 4 inserted into the housing 3, each of the pin elements 4 having a wedge surface 12c on a side near the second plate 2;and a biasing means 13 provided in the housing 3, the biasing means 13 being configured to bias the actuating pin members 4 outward in a radial direction of the housing 3. An engaging portion 10a is provided at a front end portion of the tubular wall portion 10 in its axial direction, and the engaging portion 10a protrudes inward in a radial direction of the tubular wall portion 10. When the actuating pin members 4 are pushed into the housing 3 against a biasing force of the biasing means 13, each wedge surface 12c is disengaged from the engaging portion 10a to allow the second member 5 to be detached from the first member 8.

[0018] The element changer of this aspect described above offers the following functions and effects.

[0019] The second element is removed by inserting the actuating pin elements into the housing. This makes it possible to change the second element without using a handle.

[0020] The element changer of the above aspect may be arranged so that: as for example in Fig. 11A and Fig. 11B, a projection 20 is provided at a central portion of the housing 3; a recess 19 into which the projection 20 is to be fitted is provided at a central portion of the first plate 1; and a positioning pin 22 adapted to be fitted into a pin hole 21 of the first plate 1 is provided so as to project from the housing 3, the pin hole 21 being provided at a portion of the first plate 1 other than its central portion.

[0021] With this arrangement, the circumferential position of the first plate relative to the housing is always the same. Consequently, the position of the second element relative to the first element, to which the second element is attached via the element changer, is determined with respect to the circumferential direction.

[0022] Furthermore, the element changer of the above aspect may be arranged as follows. A front end portion 23 of the positioning pin 22 has a shape such that: the front end portion 23, when inserted into the pin hole 21, contacts an inner wall surface of the pin hole 21 in a circumferential direction of the first plate 1; and one or more gaps are created between the front end portion 23 and the inner wall surface of the pin hole 21 in a radial direction of the first plate 1.

[0023] This arrangement improves the accuracy of the position of the second element in the circumferential direction relative to the first element to which the second element is attached via the element changer.

[0024] Furthermore, the element changer of any aspect may be arranged as follows. Each of the operating pin elements 4 includes: a wedge element 12 on which the wedge surface 12c is provided; an operating pin 16 inserted into a tubular hole 12a provided in the wedge element 12; and an annular elastic element 17 mounted between the operating pin 16 and the wedge element 12.

[0025] With this arrangement, each actuating pin element can be easily manufactured. Advantageous effects of the invention

[0026] According to embodiments of the element changer of the present invention, it is possible to change an element (second element) without using a handle. Brief description of the drawings [ Fig. 1A] Fig. 1A shows a first embodiment of the present invention and is a cross-sectional view of an element changer (a tool changer) along its axial direction through which a second element (tool) has been attached to a first element (robot arm). [ Fig. 1B] Fig. 1B is a cross section along a line 1B-1B in Fig. 1A. [ Fig. 2A] Fig. 2A is a diagram showing Fig. 1A and a state in which Fig. 1A shown actuating pin elements have been inserted. [ Fig. 2B] Fig. 2B is a cross section along a line 2B-2B in Fig. 2A. [ Fig. 3A] Fig. 3A is a diagram showing Fig. 1A and a state in which the Fig. 2A shows the second element (tool) removed. [ Fig. 3B] Fig. 3B is a cross section along a line 3B-3B in Fig. 3A. [ Fig. 4A] Fig. 4A is a diagram showing Fig. 1A and a state in which Fig. 3A have moved outward in a radial direction of a housing. [ Fig. 4B] Fig. 4B is a cross section along a line 4B-4B in Fig. 4A. [ Fig. 5A] Fig. 5A is a cross section along a line 5A-5A in Fig. 1A. [ Fig. 5B] Fig. 5B is a cross section along a line 5B-5B in Fig. 5A. [ Fig. 6] Fig. 6 is a perspective view of the Fig. 4A shown element changer (tool changer). [ Fig. 7A] Fig. 7A shows a second embodiment of the present invention and is a cross-sectional view of an element changer (a tool changer) along its axial direction, through which a second element (tool) has been attached to a first element (robot arm). [ Fig. 7B] Fig. 7B is a cross section along a line 7B-7B in Fig. 7A. [ Fig. 8A] Fig. 8A is a diagram showing Fig. 7A and a condition in which the Fig. 7A shown actuating pin elements have been inserted. [ Fig. 8B] Fig. 8B is a cross section along a line 8B-8B in Fig. 8A. [ Fig. 9A] Fig. 9A is a diagram showing Fig. 7A and a condition in which the Fig. 8A shows the second element (tool) removed. [ Fig. 9B] Fig. 9B is a cross section along a line 9B-9B in Fig. 9A. [ Fig. 10A] Fig. 10A is a diagram showing Fig. 7A and a state in which the Fig. 9A have moved outward in a radial direction of a housing. [ Fig. 10B] Fig. 10B is a cross section along a line 10B-10B in Fig. 10A. [ Fig. 11A] Fig. 11A is a cross section along a line 11A-11A in Fig. 7A. [ Fig. 11B] Fig. 11B is a cross section along a line 11B-11B in Fig. 11A. [ Fig. 12A] Fig. 12A is a diagram showing a modification of the element changer (tool changer) and Fig. 7A. [ Fig. 12B] Fig. 12B is a cross section along a line 12B-12B in Fig. 12A. [ Fig. 13] Fig. 13 is a diagram showing a modification of the element changer (tool changer) and Fig. 11B. Description of embodiments

[0027] Fig. 1A to Fig. 6 show a first embodiment of the present invention. A tool changer serving as an element changer is used to attach / detach a tool 5 serving as a second element, such as a machine tool, a clamp, a pallet, and a jig, to / from a robot arm 8 serving as a first element. The tool changer is configured, for example, as follows.

[0028] For example in Fig. As shown in Figure 1A, the tool changer includes: a connecting plate 1 acting as a first plate; a tool plate 2 acting as a second plate; a housing 3; and a plurality of actuating pin members 4.

[0029] A projection 9 provided at a central portion of an upper surface of the connecting plate 1 is fitted into a recess 8a provided at a distal end portion of the robot arm 8. The connecting plate 1 has, in its central portion, a tubular hole 19 concentric with the projection 9. A projection 7 provided at a central portion of an upper surface of the housing 3 is fitted into the tubular hole 19, and the housing 3 is attached to the robot arm 8 via the connecting plate 1 with a bolt or the like (not shown).

[0030] Meanwhile, a recess 6a provided at a central portion of a lower surface of the tool plate 2 is fitted onto a base end portion of the tool 5 via a projection 5a, and the tool plate 2 is attached to the tool 5 with a bolt or the like (not shown). The tool plate 2 includes a tubular wall portion 10 extending from an outer peripheral edge portion of the tool plate 2 in its axial direction.

[0031] The housing 3 has a diameter smaller than that of the tool plate 2. In the housing 3, there are receiving spaces 11, in each of which the actuating pin elements 4 are arranged. Each receiving space 11 is a hollow space extending from an outer peripheral surface of the housing 3 toward a central portion of the housing 3. Each has a small-diameter portion 11a near the central portion of the housing 3 and a widened portion 11b near the outer peripheral surface of the housing 3. In this embodiment, two receiving spaces 11 are arranged in a straight line. The two receiving spaces 11 communicate with each other in this embodiment, but need not communicate with each other.

[0032] Each actuating pin member 4 includes a wedge member 12 disposed in the corresponding widened portion 11b. Springs 13 (coil springs) functioning as biasing means configured to bias the actuating pin members 4 (wedge members 12) outward in the radial direction of the housing 3 are disposed in the respective receiving spaces 11. Furthermore, a tubular spring seat 14 is disposed in each small-diameter portion 11a to accommodate the corresponding spring 13. Each inner corner portion 15 of each widened portion 11b is a hollow portion having an arc shape and protruding outward.

[0033] Each actuating pin element 4 includes: the wedge element 12; and an actuating pin 16 inserted into a tubular hole 12a provided in the wedge element 12. The actuating pin 16 includes a pin head portion 16a, a pin portion 16b having a diameter smaller than that of the pin head portion 16a, and a stepped portion 16c between the pin head portion 16a and the pin portion 16b. The stepped portion 16c prevents the corresponding wedge element 12 from falling out of the actuating pin 16 in a direction toward the pin head portion 16a. An O-ring 17, which functions as an annular elastic member, is installed between the pin portion 16b and the wedge element 12. The O-ring 17 prevents the actuating pin 16 from coming out of the tubular hole 12a of the wedge element 12.

[0034] Retaining pins 18 are provided to protrude from a lower surface of the connecting plate 1. A head portion of each retaining pin 18 is located in a groove 12b provided on an upper surface of the corresponding wedge member 12. Each wedge member 12 has a wedge surface 12c provided on its upper surface (surface near the connecting plate 1). The wedge surface 12c is configured to engage with an engaging portion 10a of the tubular wall portion 10. The engaging portion 10a is provided at a front end portion of the tubular wall portion 10 in its axial direction and protrudes inward in the radial direction of the tubular wall portion 10.

[0035] For example in Fig. As shown in Figure 6, the tubular wall portion 10 has U-shaped indentations 10b. Each actuating pin 16 extends outwardly from the housing 3 in its radial direction beyond the corresponding indentation 10b.

[0036] Furthermore, the tool plate 2 has a hole 6b in a central portion of its upper surface, which is concentric with the recess 6a. A projection 20 provided at a central portion of a lower surface of the housing 3 is fitted into the hole 6b.

[0037] As in Fig. 5A and Fig. As shown in Figure 5B, the tool plate 2 has a pin hole 21 in a portion other than its central portion. A positioning pin 22 adapted to be inserted into the pin hole 21 is provided on the lower surface of the housing 3 in such a way as to protrude.

[0038] A front end portion 23 of the positioning pin 22 has a shape such that: its four peripheral portions are cut off; and the end portion 23 is in contact with an inner wall surface of the pin hole 21 in the circumferential direction of the tool plate 2, while small gaps are generated between the front end portion 23 and the inner wall surface of the pin hole 21 in a radial direction of the tool plate 2.

[0039] The tool changer with the structure described above works as follows.

[0040] In a Fig. 1A and Fig. In the locking state shown in FIG. 1B, in which the tool 5 was attached to the robot arm 8, the two actuating pin members 4 were moved outward in the radial direction of the housing 3 by the biasing force of the springs 13, and the wedge surface 12c of each wedge member 12 engaged with the engaging portion 10a provided at the front end portion of the tubular wall portion 10 of the tool plate 2. In this state, the wedge surfaces 12c, which are inclined relative to the direction in which the springs 13 expand and contract, push the engaging portion 10a of the tubular wall portion 10 toward the connecting plate 1. As a result, the tool 5 attached to the tool plate 2 is pulled toward the robot arm 8 and is firmly attached to the robot arm 8 via the tool changer.

[0041] In order to remove the tool 5 from the robot arm 8, the two actuating pin elements 4 are pushed into the housing 3 with fingers or the like against the pretensioning force of the springs 13, as shown in Fig. 2A and Fig. 2B. This disengages the wedge surfaces 12c from the engaging portion 10a, and the wedge elements 12 are moved inward relative to the engaging portion 10a (its inner peripheral surface) of the tubular wall portion 10. This allows the tool 5 to be removed from the robot arm 8.

[0042] As in Fig. 3A and Fig. 3B, the tool 5 is removed from the robot arm 8, for example by lowering the tool 5 with the actuating pin elements 4 pushed into the housing 3. Thereafter, the fingers are removed from the two actuating pin elements 4. As a result, the two actuating pin elements 4 are moved outward in the radial direction of the housing 3 by the biasing force of the springs 13, as shown in Fig. 4A and Fig. 4B shown.

[0043] For example, to attach the tool 5 to the robot arm 8, the tool plate 2, to which the tool 5 has already been attached, is moved to cover the housing 3, while the two actuating pin members 4 are pushed into the housing 3 with fingers or the like against the biasing force of the springs 13. During this process, the pin hole 21 of the tool plate 2 is aligned with the positioning pin 22 protruding from the lower surface of the housing 3.

[0044] After the pin hole 21 has been fitted over the front end portion 23 of the positioning pin 22 and the housing 3 is completely covered with the tool plate 2, the fingers are removed from the two actuating pin elements 4. As a result, the two actuating pin elements 4 move outward in the radial direction of the housing 3 due to the biasing force of the springs 13, and the wedge surfaces 12c of the wedge elements 12 are engaged with the engaging portion 10a provided at the front end portion of the tubular portion 10 of the tool plate 2 to position the device in the Fig. 1A and Fig. 1B shown locking state.

[0045] The pin hole 21 is fitted over the front end portion 23 of the positioning pin 22, and the hole 6b of the tool plate 2 is fitted over the projection 20 of the housing 3. Thus, the tool plate 2 is positioned at two points relative to the housing 3. This facilitates positioning and fixing of the tool plate 2 parallel to the housing 3. Furthermore, the pin hole 21 is fitted over the positioning pin 22, in contact with the pin 22 with respect to the circumferential direction of the tool plate 2. As a result, the tool plate 2 is accurately positioned relative to the housing 3 at a predetermined position in a rotational direction about the axis of the housing 3.

[0046] The tool changer described above offers the following functions and effects.

[0047] The tool changer described in Patent Literature 1 (Japanese Unexamined Patent Publication No. 2008-272875) requires a handle to change (attach / detach) a tool. In contrast, the tool changer of the above-described embodiment does not require a handle to change a tool. Moreover, the tool changer includes two (plural) operation pin members 4. Even if one of the operation pin members 4 encounters an object during the operation of the robot arm 8 and is inadvertently pushed into the housing 3, the other operation pin member 4, which is not pushed into the housing 3, prevents the tool 5 from being detached from the robot arm 8. That is, the provision of plural operation pin members 4 effectively prevents the tool 5 from being inadvertently detached from the robot arm 8.

[0048] Furthermore, the front end portion 23 of the positioning pin 22, which protrudes from the bottom surface of the housing 3, has a shape such that: the front end portion 23 contacts the inner wall surface of the pin hole 21 in the circumferential direction of the die plate 2; and small gaps are created between the front end portion 23 and the inner wall surface of the pin hole 21 in the radial direction of the die plate 2. With this arrangement, when the pin hole 21 is fitted over the front end portion 23 of the positioning pin 22 or when the front end portion 23 of the positioning pin 22 is fitted into the pin hole 21, the front end portion 23 of the positioning pin 22 is always in contact with the inner wall surface of the pin hole 21 in the circumferential direction of the die plate 2.This thus improves the positional accuracy of the tool 5 in the circumferential direction relative to the robot arm 8 to which the tool 5 is attached via the tool changer.

[0049] Fig. 7A to Fig. 11B show a second embodiment of the present invention. A tool changer of the second embodiment is constructed as follows. Main differences between the first embodiment and the second embodiment are: in the second embodiment, the housing 3 and the wedge members 12 are turned upside down; and the tubular wall portion 10 is provided on the connecting plate 1, which functions as the first plate, instead of the tool plate 2, which functions as the second plate.

[0050] As in Fig. 7A, for example, the tool changer includes a connecting plate 1, a tool plate 2, a housing 3, and a plurality of actuating pin elements 4.

[0051] A projection 9 provided at a central portion of an upper surface of the connecting plate 1 is fitted into a recess 8a provided at a distal end portion of a robot arm 8, and the connecting plate 1 is attached to the robot arm 8 with a bolt or the like (not shown). The connecting plate 1 includes a tubular wall portion 10 extending from an outer peripheral edge portion of the connecting plate 1 in its axial direction.

[0052] Meanwhile, a recess 6a provided at a central portion of a lower surface of the tool plate 2 is fitted onto a base end portion of the tool 5 via a projection 5a. The tool plate 2 has a hole 6b concentric with the recess 6a in its central portion. A projection 7 provided at a central portion of a lower surface of the housing 3 is fitted into the hole 6b, and the housing 3 is attached to the tool 5 via the tool plate 2 with a bolt or the like (not shown).

[0053] The housing 3 has a diameter smaller than that of the connecting plate 1. In the housing 3, there are receiving spaces 11, in each of which the actuating pin elements 4 are arranged. Each receiving space 11 is a hollow space extending from an outer peripheral surface of the housing 3 toward a central portion of the housing 3. Each has a small-diameter portion 11a near the central portion of the housing 3 and a widened portion 11b near the outer peripheral surface of the housing 3. In this embodiment, two receiving spaces 11 are arranged in a straight line. The two receiving spaces 11 communicate with each other in this embodiment, but need not communicate with each other.

[0054] Each actuating pin member 4 includes a wedge member 12 disposed in the corresponding widened portion 11b. Springs 13 (coil springs) functioning as biasing means configured to bias the actuating pin members 4 (wedge members 12) outward in the radial direction of the housing 3 are disposed in the respective receiving spaces 11. Furthermore, a tubular spring seat 14 is disposed in each small-diameter portion 11a to accommodate the corresponding spring 13. Each inner corner portion 15 of each widened portion 11b is a hollow portion having an arc shape and protruding outward.

[0055] Each actuating pin element 4 includes: the wedge element 12; and an actuating pin 16 inserted into a tubular hole 12a provided in the wedge element 12. The actuating pin 16 includes a pin head portion 16a, a pin portion 16b having a diameter smaller than that of the pin head portion 16a, and a stepped portion 16c between the pin head portion 16a and the pin portion 16b. The stepped portion 16c prevents the corresponding wedge element 12 from falling out of the actuating pin 16 in a direction toward the pin head portion 16a. An O-ring 17, which functions as an annular elastic member, is installed between the pin portion 16b and the wedge element 12. The O-ring 17 prevents the actuating pin 16 from coming out of the tubular hole 12a of the wedge element 12.

[0056] Retaining pins 18 are provided to protrude from the upper surface of the tool plate 2. A head portion of each retaining pin 18 is located in a groove 12b provided on a lower surface of the corresponding wedge member 12. Each wedge member 12 has a wedge surface 12c provided on its lower surface (surface near the tool plate 2). The wedge surface 12c is configured to engage with an engaging portion 10a of the tubular wall portion 10. The engaging portion 10a is provided at a front end portion of the tubular wall portion 10 in its axial direction and protrudes inward in the radial direction of the tubular wall portion 10.

[0057] The tubular wall section 10 has U-shaped indentations 10b. Each actuating pin 16 extends outward from the housing 3 in its radial direction beyond the corresponding indentation 10b.

[0058] Furthermore, the connecting plate 1 has a tubular hole 19 at its central portion, which functions as a recess. A projection 20 provided at the central portion of an upper surface of the housing 3 is fitted into the tubular hole 19.

[0059] As in Fig. 11A and Fig. As shown in Fig. 11B, the connecting plate 1 has a pin hole 21 in a portion other than its central portion. A positioning pin 22 adapted to be fitted into the pin hole 21 is provided on the upper surface of the housing 3 in such a way as to protrude.

[0060] A front end portion 23 of the positioning pin 22 has a shape such that: its four peripheral portions are cut off; and the end portion 23 is in contact with an inner wall surface of the pin hole 21 in the circumferential direction of the tool plate 2, while small gaps are generated between the front end portion 23 and the inner wall surface of the pin hole 21 in a radial direction of the tool plate 2.

[0061] The tool changer with the structure described above works as follows.

[0062] In a Fig. 7A and Fig. In the locking state shown in Fig. 7B, in which the tool 5 was attached to the robot arm 8, the two actuating pin members 4 were moved outward in the radial direction of the housing 3 by the biasing force of the springs 13, and the wedge surface 12c of each wedge member 12 engaged with the engaging portion 10a provided at the front end portion of the tubular wall portion 10 of the connecting plate 1. In this state, the wedge surfaces 12c, which are inclined relative to the direction in which the springs 13 expand and contract, push the engaging portion 10a of the tubular wall portion 10 toward the tool plate 2, and the tool 5 attached to the tool plate 2 is firmly attached to the robot arm 8 via the tool changer.

[0063] In order to remove the tool 5 from the robot arm 8, the two actuating pin elements 4 are pushed into the housing 3 with fingers or the like against the pretensioning force of the springs 13, as shown in Fig. 8A and Fig. 8B. This disengages the wedge surfaces 12c from the engaging portion 10a, and the wedge elements 12 are moved inward relative to the engaging portion 10a (its inner peripheral surface) of the tubular wall portion 10. This allows the tool 5 to be removed from the robot arm 8.

[0064] As in Fig. 9A and Fig. 9B, the tool 5 is removed from the robot arm 8, for example, by lowering the tool 5 with the actuating pin elements 4 pushed into the housing 3. Thereafter, the fingers are removed from the two actuating pin elements 4. As a result, the two actuating pin elements 4 are moved outward in the radial direction of the housing 3 by the biasing force of the springs 13, as shown in Fig. 10A and Fig. 10B shown.

[0065] For example, to attach the tool 5 to the robot arm 8, the housing 3, to which the tool 5 has already been attached via the tool plate 2, is fitted into the tubular wall portion 10 of the connecting plate 1, while the two actuating pin members 4 are pushed into the housing 3 with fingers or the like against the biasing force of the springs 13. During this process, the positioning pin 22 protruding from the upper surface of the housing 3 is aligned with the pin hole 21 of the connecting plate 1.

[0066] After the front end portion 23 of the positioning pin 22 is fitted into the pin hole 21 and after the housing 3 is fitted into the tubular wall portion 10, the fingers are removed from the two actuating pin elements 4. As a result, the two actuating pin elements 4 move outward in the radial direction of the housing 3 due to the biasing force of the springs 13, and the wedge surfaces 12c of the wedge elements 12 are engaged with the engaging portion 10a provided at the front end portion of the tubular portion 10 of the connecting plate 1 to position the device in the Fig. 7A and Fig. 7B shown locking state.

[0067] The front end portion 23 of the positioning pin 22 is fitted into the pin hole 21, and the projection 20 of the housing 3 is fitted into the tubular hole 19 of the connecting plate 1. Thus, the housing 3 is positioned at two points relative to the connecting plate 1. This facilitates positioning and fixing of the housing 3 parallel to the connecting plate 1. Furthermore, the positioning pin 22 is fitted into the pin hole 21, in contact with the pin hole 21 with respect to the circumferential direction of the connecting plate 1. Due to this, the housing 3 is accurately positioned relative to the connecting plate 1 at a predetermined position in a rotational direction about the axis of the connecting plate 1.

[0068] The embodiments described above can be modified as follows.

[0069] In each of the embodiments, each actuating pin element 4 is designed to protrude from the housing 3 in the radial direction of the housing 3 beyond the corresponding recess 10b of the tubular wall portion 10. Instead, each actuating pin element 4 inserted into the housing 3 may be arranged such that its pin head portion 16a does not protrude outward beyond the corresponding recess 10b, as shown in Fig. 12A and Fig. 12B shown.

[0070] As in Fig. 13, a plurality of positioning pins 22 may be provided. In this arrangement, for example, a first positioning pin 22A functions as a positioning pin with respect to the Y direction (the circumferential direction of the connecting plate 1 or the tool plate 2), while a second positioning pin 22B functions as a positioning pin with respect to the X direction perpendicular to the Y direction (a radial direction of the connecting plate 1 or the tool plate 2).

[0071] A front end portion 23A of the positioning pin 22A has a shape such that: the front end portion 23A in the circumferential direction of the connecting plate 1 (or the tool plate 2 in the first embodiment) is in contact with an inner wall surface of a pin hole 21A; and small gaps are formed between the front end portion 23A and the inner wall surface of the pin hole 21A in the radial direction of the connecting plate 1 (or the tool plate 2 in the first embodiment).A front end portion 23B of the positioning pin 22B has a shape such that: the front end portion 23B contacts an inner wall surface of a pin hole 21B in the radial direction of the connecting plate 1 (or the tool plate 2 in the first embodiment); and small gaps are formed between the front end portion 23B and the inner wall surface of the pin hole 21B in the circumferential direction of the connecting plate 1 (or the tool plate 2 in the first embodiment).

[0072] The projection 20 does not have to be present, as in Fig. 13. A reference numeral C represents the center of the connecting plate 1.

[0073] Instead of the arrangement in which the positioning pin(s) 22, 22A and 22B is / are provided on the housing 3 and the pin hole(s) 21, 21A and 21B is / are provided in the connecting plate 1 or the tool plate 2, the following arrangement is also possible: the positioning pin(s) 22, 22A and 22B is / are provided on the connecting plate 1 or the tool plate 2 and the pin hole(s) 21, 21A and 21B is / are provided in the housing 3.

[0074] In each of the above embodiments, the two actuating pin members 4 are arranged at intervals of (or with a phase difference of) 180 degrees in the circumferential direction of the tool changer. The interval (or phase difference) between the two actuating pin members 4 in the circumferential direction of the housing 3 (or the tool changer) is not limited to 180 degrees. For example, the two actuating pin members 4 may be arranged at an interval of (or with a phase difference of) 90 or 120 degrees.

[0075] Three or more actuating pin elements 4 can be arranged.

[0076] Each actuating pin element 4 need not be made of separate components such as the wedge element 12 and the actuating pin 16. Each actuating pin element 4 may be a unitary element made of one material and formed as an actuating pin element including a wedge portion.

[0077] Without using the O-ring 17 as a holder, each actuating pin 16 can be pressed into the tubular hole 12a of the corresponding wedge element 12.

[0078] The connecting plate 1, the tool plate 2, and the housing 3 each have a round shape in plan view. Instead of the round shape, they can each have a polygonal shape such as a square, an elliptical shape, or the like.

[0079] The projection 7 and / or the projection 20 need not be provided at the central portions as long as the device is designed so that the axis of the recess 8a of the robot arm 8 can ultimately be aligned with the axis of the projection 5a of the tool 5.

[0080] The second element, which is a removable element, may be an object undergoing a machining process, such as a machine tool, a clamp, a pallet, and a jig, instead of the tool 5. Furthermore, the first element may be a movable section of a conveyor or a table acting as a stationary stand, instead of the robot arm 8.

[0081] Embodiments of the present invention have been described above. It should be understood that other changes or modifications to the present invention may be made within the scope of what one skilled in the art would envisage. List of reference symbols

[0082] 1: Connecting plate (first plate); 2: Tool plate (second plate); 3: Housing; 4: Actuating pin member; 5: Tool (second member); 6b: Hole (recess); 8: Robot arm (first member); 10: Tubular wall portion; 10a: Engaging portion; 12: Wedge member; 12a: Tubular hole; 12c: Wedge surface; 13: Spring (biasing means); 16: Actuating pin; 17: O-ring (elastic member); 19: Tubular hole (recess); 20: Projection; 21: Pin hole; 22: Positioning pin; 23: Front end portion. QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] JP 2008-272875 [0004, 0047]

Claims

[1] Element changer, which has: a first plate (1) adapted to be attached to a first element (8); a second plate (2) adapted to be attached to a second member (5), the second plate (2) including a tubular wall portion (10) extending from an outer peripheral edge portion of the second plate (2) in its axial direction; a housing (3) adapted to be attached to the first element (8) via the first plate (1), the housing (3) having a diameter smaller than that of the second plate (2); a plurality of actuating pin elements (4) inserted into the housing (3), each of the pin elements (4) having a wedge surface (12c) on a side near the first plate (1); and a biasing means (13) provided in the housing (3), wherein the biasing means (13) is designed to bias the actuating pin elements (4) outwards in a radial direction of the housing (3), where: an engaging portion (10a) is provided at a front end portion of the tubular wall portion (10) in its axial direction, the engaging portion (10a) projecting inward in a radial direction of the tubular wall portion (10); and when the actuating pin elements (4) are pushed into the housing (3) against a biasing force of the biasing means (13), each wedge surface (12c) is disengaged from the engagement portion (10a) so that the second element (5) can be removed from the first element (8). [2] Element changer according to claim 1, wherein: a projection (20) is provided at a central portion of the housing (3); a recess (6b) into which the projection (20) is to be fitted is provided at a central portion of the second plate (2); and a positioning pin (22) adapted to be fitted into a pin hole (21) of the second plate (2) is provided so as to protrude from the housing (3), the pin hole (21) being provided at a portion of the second plate (2) other than its central portion. [3] Element changer according to claim 2, wherein a front end portion (23) of the positioning pin (22) has a shape such that: the front end portion (23), when fitted into the pin hole (21), is in contact with an inner wall surface of the pin hole (21) in a circumferential direction of the second plate (2); and one or more gaps are created between the front end portion (23) and the inner wall surface of the pin hole (21) in a radial direction of the second plate (2). [4] Element changer, which has: a first plate (1) adapted to be attached to a first member (8), the first plate (1) including a tubular wall portion (10) extending from an outer peripheral edge portion of the first plate (1) in its axial direction; a second plate (2) adapted to be attached to a second element (5); a housing (3) adapted to be attached to the second element (5) via the second plate (2), the housing (3) having a diameter smaller than that of the first plate (1); a plurality of actuating pin elements (4) inserted into the housing (3), each of the pin elements (4) having a wedge surface (12c) on a side near the second plate (2); and a biasing means (13) provided in the housing (3), wherein the biasing means (13) is designed to bias the actuating pin elements (4) outwards in a radial direction of the housing (3), where: an engaging portion (10a) is provided at a front end portion of the tubular wall portion (10) in its axial direction, the engaging portion (10a) projecting inward in a radial direction of the tubular wall portion (10); and when the actuating pin elements (4) are pushed into the housing (3) against a biasing force of the biasing means (13), each wedge surface (12c) is disengaged from the engagement portion (10a) so that the second element (5) can be removed from the first element (8). [5] Element changer according to claim 4, wherein: a projection (20) is provided at a central portion of the housing (3); a recess (19) into which the projection (20) is to be fitted is provided at a central portion of the first plate (1); and a positioning pin (22) adapted to be fitted into a pin hole (21) of the first plate (1) is provided so as to protrude from the housing (3), the pin hole (21) being provided at a portion of the first plate (1) other than its central portion. [6] Element changer according to claim 5, wherein a front end portion (23) of the positioning pin (22) has a shape such that: the front end portion (23), when fitted into the pin hole (21), is in contact with an inner wall surface of the pin hole (21) in a circumferential direction of the first plate (1); and one or more gaps are created between the front end portion (23) and the inner wall surface of the pin hole (21) in a radial direction of the first plate (1). [7] Element changer according to one of claims 1 to 6, wherein each of the actuating pin elements (4) includes: a wedge element (12) on which the wedge surface (12c) is provided; an actuating pin (16) inserted into a tubular hole (12a) provided in the wedge element (12); and an annular elastic element (17) mounted between the actuating pin (16) and the wedge element (12).

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