Positioning device

Abstract

To provide a positioning device capable of being operated reliably.SOLUTION: A clamp rod (7) is inserted into a guide hole (6) of a housing (1) so as to be movable in a vertical direction. A lock spring (18) mounted in the guide hole (6) urges the clamp rod (7) downward with respect to the housing (1). An operating rod (23) is inserted into a support hole (22) intersecting the guide hole (6) so as to be rotatable around an axial core. A cam part (25) formed on an outer peripheral wall of the operating rod (23) is engaged with a base end part of the clamp rod (7).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a positioning device that is manually operated to position and fix an object to be positioned, such as a workpiece, a work pallet, a mold, or a tool, at a predetermined position on a table, a carriage, or the movable part of a robot. [Background technology]

[0002] A conventional device for pressing or positioning a hole in a workpiece of this type is a connecting device described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2015-218814). This conventional technology is configured as follows. The above-described coupling device is attached to one member and couples the one member to the other member. The housing of the coupling member is inserted into the mounting hole of the one member and secured with a bolt. A guide hole extends vertically through the housing, and a clamp rod is inserted into the guide hole so as to be movable vertically and rotatable about its axis. A support hole extends radially through the lower cylindrical wall of the housing, and a ball is inserted into the support hole so as to be movable radially. The ball is inserted into a spiral groove formed in the lower outer peripheral wall of the clamp rod. The spiral groove is formed in the outer peripheral wall of the clamp rod so as to become deeper downward. A flange portion is formed circumferentially in the middle of the height direction of the outer peripheral wall of the clamp rod so as to protrude radially. A lock spring is attached between the flange portion and the inner peripheral wall of the housing. This lock spring urges the clamp rod downward relative to the housing. An operating grip is fixed to the upper part of the clamp rod. The operator rotates the operating grip to lock and release the coupling device. A cylindrical cam portion is formed on the upper part of the housing, and the top surface of the cylindrical wall is configured so that its height decreases clockwise in plan view. This top surface forms a cam surface. A pin slidably engaged with the cam surface protrudes horizontally from the upper outer peripheral wall of the clamp rod. A hole is formed in the other component, and a tapered locking portion is formed on the inner peripheral wall of the hole, the diameter of which decreases upward. The ball can engage with this locking portion. In the release state of the coupling device, the pin of the clamp rod is moved near the upper limit position of the cam surface, and the release state is maintained by the downward biasing force of the lock spring. To switch the coupling device from the release state to the lock state, the operator rotates the operating grip clockwise in plan view. The downward biasing force of the lock spring and the external force of the operator rotate and lower the clamp rod. The ball is then pushed radially outward along the spiral groove of the clamp rod, engaging with the locking portion of the other component. This switches the connecting member from the release state to the lock state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-218814 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned prior art has the following problems. When switching the above-mentioned coupling device from the released state to the locked state, the operator applies an external force in the rotational direction to the operating grip, and the downward biasing force of the lock spring acts on the clamp rod. This causes the peripheral wall of the spiral groove of the clamp rod to engage with the locking portion of the other component via the ball. At this time, the frictional forces acting on contact points, such as between the locking portion of the other component and the ball, between the ball and the spiral groove, and between the pin and the cam surface, increase with increasing use. In such cases, the operator may sense the frictional forces during the rotational operation and mistakenly believe that the coupling device is in a locked state when it is not. Furthermore, if the operator operates the operating grip too forcefully, taking the frictional forces into consideration, the contact points may wear or break. SUMMARY OF THE INVENTION An object of the present invention is to provide a positioning device that can be operated reliably. [Means for solving the problem]

[0005] In order to achieve the above object, the present invention provides a positioning device configured as follows, as shown in, for example, FIGS. 1A to 2B, 3A, and 3B. A cylindrical plug portion 5 is formed at the tip end of the housing 1. A clamp rod 7 is inserted into a guide hole 6 formed in the plug portion 5 so as to be axially movable. A cylindrical pressing member 11 is attached to the outer periphery of the tip end of the clamp rod 7 and is made of an elastic member. The pressing member 11 has a slit 13 and is slidably engaged with a wedge portion 16 formed on the outer periphery wall of the plug portion 5. A lock spring 18 attached in the guide hole 6 biases the clamp rod 7 toward the base end in the axial direction relative to the housing 1. An operating rod 23 is inserted into a support hole 22 formed in the housing 1 so as to intersect with the guide hole 6 so as to be rotatable about its axis. A cam portion 25 formed on the outer periphery wall of the operating rod 23 engages with the base end of the clamp rod 7. An insertion portion 44 is formed on the outer periphery wall of the operating rod 23. The insertion portion 45 is provided adjacent to the cam portion 25, with a step portion 44 formed in a substantially radial direction of the operating rod 23 interposed therebetween. The clamp rod 7 can be inserted into the insertion portion 44 .

[0006] The present invention provides the following advantageous effects. When the positioning device is switched from the released state to the locked state, the clamp rod is reliably operated by the biasing force of the lock spring to move from a state where it is pressed against the cam portion to a state where it straddles the step portion and is inserted into the insertion portion. At this time, the operator can feel a sudden decrease in resistance from the operating rod when rotating it, or feel vibration, or hear the sound of insertion. This allows the operator to reliably recognize that the positioning device has been switched from the released state to the locked state.

[0007] The present invention preferably includes the following features (1) and (2). (1) For example, as shown in FIGS. 1A to 2B and 3B, the positioning device is configured as follows. A slide hole 29 formed in the housing 1 opens to the inner peripheral surface of the support hole 22. A locking member 30 is urged toward the operating rod 23 by an advancing spring 31 housed in the slide hole 29. The locking member 30 is insertable into a recess 33 formed in the outer peripheral wall of the operating rod 23. In this case, the locking member is inserted into the recess when the operating rod is rotated about its axis and the recess faces the tip of the locking member. Therefore, even if the operator stops operating the operating rod, the state of the positioning device at that time is reliably maintained. Furthermore, at this time, the operator can reliably recognize that the operating rod has reached the predetermined position in the rotational direction by the sound and vibration generated during insertion and the resistance force of the locking member and the advancement spring acting to prevent the operating rod from rotating. (2) For example, as shown in FIG. 3A, the positioning device is configured as follows. A recess 46 is formed in the base end of the cam portion 25 or the clamp rod 7. A protrusion 47 protrudes from the base end of the clamp rod 7 or the cam portion 25 of the operating rod 23 toward the recess 46. In this case, the operating rod is rotated about its axis, and the convex portion is inserted into the concave portion. Therefore, even if the operator stops operating the operating rod, the state of the positioning device at that time is reliably maintained. Furthermore, at this time, the operator can reliably recognize that the operating rod has reached the predetermined position in the rotation direction due to the sound and vibration generated during insertion and the resistance force generated by the convex portion and the concave portion that prevents the operating rod from rotating. [Brief explanation of the drawings]

[0008] [Figure 1] Fig. 1A is a cross-sectional view of an embodiment of the present invention showing a positioning device in a released state. Fig. 1B is a view taken along line 1B-1B in Fig. 1A. Fig. 1C is an external view of the positioning device. [Figure 2] Figure 2A is a view similar to Figure 1A showing the positioning device in a locked state, and Figure 2B is an external view of the positioning device similar to Figure 1C. [Figure 3] Figure 3A shows a first variant of the embodiment of the invention and is a view similar to Figure 1A. Figure 3B shows a second variant of the embodiment of the invention and is a view similar to Figure 1A. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1A to 2B. In the above positioning device, a small-diameter lower portion 3 protrudes downward from a main body portion 2 of a housing 1. The lower portion 3 of the housing 1 is inserted into a mounting hole formed in a table T. The main body portion 2 of the housing 1 is fixed to the table T with a bolt 4. A cylindrical plug portion 5 protrudes upward from the main body portion 2.

[0010] A guide hole 6 as a cylindrical hole of the plug portion 5 is formed in the vertical direction, and a main body portion 8 of a clamp rod 7 is inserted into the guide hole 6 so as to be movable in the vertical direction. An upper portion of the main body portion 8 protrudes upward from the housing 1. A disk-shaped support portion 9 is integrally formed above the main body portion 8 and concentrically with the main body portion 8, and the support portion 9 has a diameter larger than that of the main body portion 8.

[0011] An attachment groove 10 is formed in the circumferential direction on the outer peripheral wall of the support portion 9. A pressing member 11 is attached to the attachment groove 10. The pressing member 11 of this embodiment is made of an elastic material that is elastically deformed by an external force, such as a spring material, resin, or rubber, and is elastically deformed so as to expand radially outward when the external force is applied. When the external force is no longer acting on the pressing member 11, the elastic restoring force of the pressing member 11 causes it to contract radially inward.

[0012] The main body 12 of the pressing member 11 is cylindrical and has a slit 13 formed by dividing the cylindrical wall at one location. Pawls 14 are formed circumferentially from the upper part of the inner peripheral wall of the main body 12 so as to protrude radially inward. A receiving surface 15 is formed on the inner peripheral wall of the main body 12, below the pawls 14, and is inclined so as to widen downward. The receiving surface 15 of the pressing member 11 is slidably engaged with a wedge surface 16 formed on the outer peripheral wall of the plug portion 5 of the housing 1. The wedge surface 16 is formed on the outer peripheral wall of the plug portion 5 so as to widen downward (moving away from the axis of the guide hole 6). Therefore, when the clamp rod 7 and the pressing member 11 are moved downward, the pressing member 11 is moved downward along the wedge surface 16 and is pushed radially outward. Furthermore, as the clamp rod 7 and the pressing member 11 are moved upward, the pressing member 11 is moved radially inward by its elastic restoring force.

[0013] A flange portion 17 is formed radially outward from the lower end of the clamp rod 7, continuing in the circumferential direction. A lock spring 18 is attached inside the guide hole, between the upper surface of the flange portion 17 and the ceiling surface of the guide hole 6. The lower end of the lock spring 18 engages with the flange portion 17, and the upper end of the lock spring 18 engages with the ceiling wall of the guide hole 6. As a result, the lock spring 18 urges the clamp rod 7 downward relative to the housing 1.

[0014] A recess 19 is formed in the upper outer peripheral wall of the main body 8 of the clamp rod 7, and a ball 20 is fitted in the recess 19. The ball 20 is slidably inserted into a linear guide groove 21 formed in the vertical direction on the inner peripheral wall of the guide hole 6 of the plug portion 5. This allows the clamp rod 7 to move vertically relative to the housing 1, while restricting its rotation around its axis.

[0015] A support hole 22 penetrates the housing 1 in the horizontal direction, and is formed so as to be perpendicular to (intersect with) the guide hole 6. An operating rod 23 is inserted into the support hole 22 so as to be rotatable about the axis of the support hole 22. One end 23a of the operating rod 23 is slidably supported by an inner circumferential wall 22a of the support hole 22, and the other end 23b of the operating rod 23 is slidably supported by an inner circumferential wall 22b of the support hole 22.

[0016] Two cam grooves 24 are formed between one end 23a and the other end 23b of the operating rod 23 so as to be continuous in the circumferential direction. As shown in FIG. 1A, the cam grooves 24 are formed on the outer peripheral wall of the operating rod 23 so as to become deeper in the clockwise direction. The bottom or side surfaces of the cam grooves 24 form a cam portion 25. The lower end surface of the clamp rod 7 engages with the cam portion 25. Therefore, when the operating rod 23 is rotated about its axis, the cam portion 11 moves the clamp rod 7 upward in the axial direction against the downward biasing force of the lock spring 18.

[0017] A pin hole 26 for preventing disengagement is formed in the vertical direction in the main body 2 of the housing 1, and a pin 27 inserted into the pin hole 26 is also inserted into a groove 28 formed in the circumferential direction in the outer peripheral wall on one end side of the operating rod 23. Therefore, the operating rod 23 is prevented from disengaging from the support hole 22 by the pin hole 26, the pin 27, and the groove 28.

[0018] A slide hole 29 is formed horizontally in the side wall of the housing 1, and the slide hole 29 opens to the inner circumferential surface of the support hole 22. A locking member 30 and an advancing spring 31 are housed in the slide hole 29, and a cover member 32 is screwed into the slide hole 29. The advancing spring 31 biases the locking member 30 toward the support hole 22 relative to the housing 1. The tip of the locking member 30 is formed in a hemispherical shape and is insertable into two recesses 33 formed at a predetermined interval (180° apart in this embodiment) on the outer circumferential wall of the operating rod 23. Therefore, when the operating rod 23 is rotated about its axis and the recesses 33 face the tip of the locking member 30, the locking member 30 is inserted into the recesses 33. When the operating rod 23 is further rotated, the inner circumferential wall of the recesses 33 presses the locking member 30 into the slide hole 29 against the biasing force of the advancing spring 31.

[0019] One end 22a of the support hole 22 opens into the outer surface of the housing 1, and one end 23a of the operating rod 23 protrudes from the housing 1. A hexagonal hole 34 is formed in one end wall 23a of the operating rod 23, and a tool, for example, a hexagonal wrench 43 can be inserted into the hexagonal hole 34. Two triangular marks 35 are engraved by a laser on the radially outer side of the hexagonal hole 34 at one end 23a of the operating rod 23, facing radially outward at 180-degree intervals, and a clockwise arrow 36 is engraved between one of the triangular marks 35 and the other triangular mark 35. Furthermore, two triangular marks 37 are engraved by a laser on the outer side of the outer peripheral wall of the operating rod 23, facing radially inward of the support hole 22 at 180-degree intervals, and the word "OFF" is engraved radially outward of the triangular marks 37. Furthermore, curved lines 38 are engraved at predetermined intervals in the clockwise direction from each triangular mark 37, and the word "ON" is engraved outside the curved lines 38.

[0020] The positioning device described above, as shown in FIGS. 1A to 2B, operates as follows. 1A to 1C, in the initial state (release state), the triangular mark 35 of the operating rod 23 faces the OFF position and the triangular mark 37 of the housing 1, and the locking member 30 is inserted into the recess 33 of the operating rod 23. In addition, the lower end surface of the clamp rod 7 is engaged with a portion 39 on the outer circumferential surface of the operating rod 23, which is far away from the axis of the operating rod 23 in the radial direction. Therefore, the clamp rod 7 and the pressing member 11 are moved to the upper limit position, and the pressing member 11 is contracted radially inward by its own elastic restoring force.

[0021] An operator carries in the workpiece 40 from above the positioning device in the released state, and fits the hole 41 of the workpiece 40 onto the clamp rod 7. Thereafter, the workpiece 40 is placed on a placing table 42 on the table T.

[0022] When switching the positioning device from the release state to the lock state, the operator rotates the tool 43 inserted into the hexagonal hole 34 of the operating rod 23 clockwise. Then, due to the biasing force of the lock spring 18, the clamp rod 7 moves from a state in which it is engaged with a portion 39 of the operating rod 23 (a large-diameter portion of the operating rod 23) radially spaced from the axis of the operating rod 23 to a step portion 44 formed approximately in the radial direction of the operating rod 23 and inserted into an insertion portion 45 (a small-diameter portion relative to the large-diameter portion of the operating rod 23). As a result, the pressing member 11 is lowered along the wedge surface 16 of the housing 1 and expands radially outward. When the outer peripheral surface of the pressing member 11 engages with the inner peripheral surface of the hole 41 of the workpiece 40, the lowering of the clamp rod 7 is stopped. This switches the positioning device from the release state to the lock state. As a result, the positioning device positions the workpiece 40 at a predetermined position on the table T. When the positioning device is in the locked state, the triangular mark 35 engraved on one end face of the operating rod 23 is rotated to a position facing the curved line 38 engraved on the side wall of the housing 1. This allows the operator to confirm that the positioning device is in the locked state.

[0023] When switching the positioning device from the locked state to the released state, the operator rotates the tool 43 inserted into the hexagonal hole 34 of the operating rod 23 clockwise. This causes the lower end surface of the clamp rod 7 to engage with the cam portion 25 of the operating rod 23, which then pushes the clamp rod 7 upward against the downward biasing force of the lock spring 18. Next, when the lock member 30 is inserted into the recess 33 of the operating rod 23, the operator stops rotating the tool 43. This switches the positioning device from the locked state to the released state.

[0024] The above embodiment has the following advantages. When the positioning device is switched from the released state to the locked state, the clamp rod 7 is reliably operated by the biasing force of the lock spring 18 to change from a state in which it is pressed against the cam portion 25 to a state in which it straddles the stepped portion 44 and is inserted into the insertion portion 45. At this time, the operator can feel a sudden decrease in resistance from the operating rod 23 when rotating it, or can sense vibration, or hear the sound of insertion. This allows the operator to reliably recognize that the positioning device has been switched from the released state to the locked state.

[0025] 3A and 3B show first and second modified examples of the above embodiment. In these first and second modified examples, components that are the same as (or similar to) those in the above embodiment are generally designated by the same reference numerals. The first modification of this embodiment differs from the above embodiment in the following respects.

[0026] 3A, the positioning device of the first modified embodiment has only one cam portion 25 provided on the outer peripheral wall of the operating rod 23. This allows the operator to set a large vertical movement distance for the clamp rod 7 without increasing the force with which the operator rotates the operating rod 23.

[0027] In the above-described positioning device, the housing 1 does not have a slide hole 29, and the locking member 30 and the advancement spring 31 are not provided. Furthermore, the outer peripheral wall of the operating rod 23 does not have a recess 33. In a first modification of this embodiment, a recess 46 is formed in the cam portion 25, and a protrusion 47 insertable into the recess 46 is provided on the lower part of the clamp rod 7. The protrusion 47 is configured, for example, as follows: A pin is inserted into an attachment hole formed horizontally on the lower end of the clamp rod 7. The lower peripheral wall of the pin protrudes downward from the lower end surface of the clamp rod, and the lower end surface of the pin forms the protrusion 47. Furthermore, a ball is inserted into an attachment hole opened on the lower end surface of the clamp rod 7. The lower half of the ball protrudes downward, and the lower part of the ball forms the protrusion 47. Therefore, when switching the positioning device from a locked state to a released state, the operating rod 23 is rotated clockwise until the position 39 on the cam portion 25 that is farthest from the axis approaches the vicinity of the protrusion 47 of the clamp rod 7, and the downward biasing force of the lock spring 18 causes the protrusion 47 to be inserted into the recess 46 of the operating rod 23. At this time, the operator can sense the engagement by the sound and vibration caused by the engagement, and knows that the positioning device has entered the released state.

[0028] The peripheral wall of the recess 46 is inclined so that the peripheral wall on the clockwise side, as viewed from the bottom position where the recess 46 is deepest, is at an acute angle relative to the radial direction compared to the peripheral wall on the counterclockwise side. In FIG. 3A , the right wall of the recess 46 is inclined by α° relative to the radial direction, while the left wall of the recess 46 is inclined by β° relative to the radial direction. α°<β°. Therefore, when turning the operating rod 23 in the clockwise direction, a relatively small force is required to overcome the peripheral wall of the recess 46. However, when an operator attempts to turn the operating rod 23 in the counterclockwise direction, the operator finds it more difficult to turn the operating rod 23 than in the clockwise direction. This prevents the operator from turning the operating rod 23 in the wrong direction.

[0029] 3B, the positioning device of the second modified embodiment has four cam portions 25 provided on the outer peripheral wall of the operating rod. This allows the operator to lock and release the positioning device by rotating the operating rod 23 by a smaller angle, about 90°, than in the positioning device of the above embodiment.

[0030] The above embodiments can be modified as follows. The housing 1 may be fixed to a work pallet, a movable tip of a robot hand, an automatic guided vehicle, or the like, instead of being fixed to the table T. In this case, the object to be positioned may be a work pallet, a tool, or the like, instead of the workpiece 40. Instead of providing the operating rod 23 with the hexagonal hole 34 for inserting a tool, an operating lever or knob may be fixed to one end of the operating rod 23. Also, instead of the operating rod 23 being manually operated by an operator, the operating rod 23 may be operated by a robot or an electric tool. In this embodiment, the inclination angle of the wedge surface 16 of the plug portion 5 is 4° to 8° with respect to the axis of the guide hole 6, but is not limited to this and may be changed. In this case, if the inclination angle is made steeper (the angle is made smaller), the force with which the pressing member 11 presses against the inner circumferential surface of the hole 41 in the workpiece 40 can be increased. Also, if the inclination angle is made gentler (the angle is made larger), the amount of movement of the clamp rod 7 can be kept small. In the first modified example of the above embodiment, instead of forming the recess 46 in the cam portion 25 of the operating rod 23, a recess may be opened in the lower end surface of the clamp rod 7. In this case, instead of providing the protrusion 47 protruding downward from the lower end surface of the clamp rod 7, the protrusion 47 may be provided protruding upward from the cam portion 25 of the operating rod 23. Of course, various other modifications can be made within the scope of what can be imagined by those skilled in the art. [Explanation of symbols]

[0031] 1: Housing, 5: Plug part, 6: Guide hole, 7: Clamp rod, 11: Pressing member, 13: Slit, 16: Wedge part, 18: Lock spring, 22: Support hole, 23: Operating rod, 25: Cam part, 29: Slide hole, 31: Advance spring, 30: Lock member, 33: Recess, 46: Recess, 46: Convex part.

Claims

1. a cylindrical plug portion (5) formed at the tip end of the housing (1); a clamp rod (7) inserted axially movably into a guide hole (6) formed in the plug portion (5); a cylindrical pressing member (11) made of an elastic material and attached to the outer periphery of the distal end of the clamp rod (7), the pressing member (11) having a slit (13) and slidably engaging with a wedge portion (16) formed on the outer periphery wall of the plug portion (5); a lock spring (18) that is mounted in the guide hole (6) and biases the clamp rod (7) toward the base end in the axial direction relative to the housing (1); an operating rod (23) rotatably inserted about its axis into a support hole (22) formed in the housing (1) so as to intersect with the guide hole (6); a cam portion (25) formed on the outer peripheral wall of the operating rod (23) and engaged with the base end of the clamp rod (7); and an insertion portion (45) formed on the outer peripheral wall of the operating rod (23) and arranged adjacent to the cam portion (25) across a step portion (44) formed on the operating rod (23) in the approximate radial direction of the operating rod (23), into which the clamp rod (7) can be inserted.

2. 2. The positioning device according to claim 1, a slide hole (29) formed in the housing (1) and opening on the inner circumferential surface of the support hole (22); a locking member (30) that is biased toward the operating rod (23) by an advancing spring (31) housed in the sliding hole (29), and that is insertable into a recess (33) formed in the outer peripheral wall of the operating rod (23).

3. 2. The positioning device according to claim 1, a recess (46) formed in the base end of the cam portion (25) or the clamp rod (7); A positioning device characterized by comprising a protrusion (47) that protrudes from the base end of the clamp rod (7) or the cam portion (25) toward the recess (46) so as to be insertable into the recess (46).

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