JP7807741B2 - Positioning device - Google Patents

Description

This invention relates to a positioning device that, when manually operated, positions and fixes objects to be positioned, such as workpieces, work pallets, molds, and tools, in a predetermined position on a table, a carriage, or the moving part of a robot.

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.

Japanese Patent Application Laid-Open No. 2015-218814

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.

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. An 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 sandwiched therebetween. The clamp rod 7 can be inserted into the insertion portion 44 .

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.

The present invention preferably includes the following configurations (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 projects 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.

Fig. 1A is a schematic cross-sectional view showing a positioning device in a released state according to an embodiment of the present invention. Fig. 1B is a view taken along line 1B-1B in Fig. 1A. Fig. 1C is an external view of the positioning device. Figure 2A is a view similar to Figure 1A showing the positioning device in a locked state, and Figure 2B is an external view showing the positioning device, similar to Figure 1C. 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.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1A to 2B.
In the above-described positioning device, a small-diameter lower portion 3 protrudes downward from a main body 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 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 2.

The plug portion 5 has a guide hole 6 formed in the vertical direction as a cylindrical hole, and the main body portion 8 of the clamp rod 7 is inserted into this guide hole 6 so that it can move up and down. The upper part 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 concentric with the main body portion 8, and the support portion 9 has a larger diameter than the main body portion 8.

A mounting groove 10 is formed in the circumferential direction on the outer peripheral wall of the support portion 9. A pressing member 11 is mounted in this mounting groove 10. In this embodiment, the pressing member 11 is made of an elastic material that elastically deforms in response to an external force, such as a spring material, resin, or rubber, and is elastically deformed so as to expand radially outward in response to the external force. 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.

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. A claw 14 is formed circumferentially so as to protrude radially inward from the upper part of the inner peripheral wall of the main body 12. A receiving surface 15 is formed on the inner peripheral wall of the main body 12, below the claw 14, and is inclined so as to widen as it extends 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 as it extends downward (away from the axis of the guide hole 6). Therefore, when the clamp rod 7 and pressing member 11 are moved downward, the pressing member 11 is moved downward along the wedge surface 16 and is pushed radially outward. Furthermore, when 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.

A flange portion 17 extends radially outward from the lower end of the clamp rod 7, continuing circumferentially. A lock spring 18 is attached within the guide hole, between the upper surface of the flange portion 17 and the ceiling wall 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 biases the clamp rod 7 downward relative to the housing 1.

A recess 19 is formed in the upper outer peripheral wall of the main body portion 8 of the clamp rod 7, and a ball 20 is attached to this 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 rotation of the clamp rod 7 around its axis.

A support hole 22 penetrates the housing 1 horizontally and is formed so as to intersect with the guide hole 6 at right angles. 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 on the inner peripheral wall 22a of the support hole 22, and the other end 23b of the operating rod 23 is slidably supported on the inner peripheral wall 22b of the support hole 22.

Two cam grooves 24 are formed between one end 23a and the other end 23b of the operating rod 23 so that they are 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 that they 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 axially upward against the downward biasing force of the lock spring 18.

A pin hole 26 for preventing dislodgement is formed in the vertical direction in the main body 2 of the housing 1, and a pin 27 inserted into this pin hole 26 is also inserted into a groove 28 formed circumferentially in the outer wall of one end of the operating rod 23. Therefore, the operating rod 23 is prevented from dislodgement from the support hole 22 by the pin hole 26, pin 27, and groove 28.

A sliding hole 29 is formed horizontally in the side wall of the housing 1, and opens into the inner circumferential surface of the support hole 22. A locking member 30 and an advancement spring 31 are housed within the sliding hole 29, and a cover member 32 is threadedly engaged with the sliding hole 29. The advancement 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 hemispherically so that it can be inserted into two recesses 33 formed at a predetermined distance (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 pushes the locking member 30 into the sliding hole 29 against the biasing force of the advancement spring 31.

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, into which a tool, such as a hexagonal wrench 43, can be inserted. Two triangular marks 35 are laser-engraved on the radially outer side of the hexagonal hole 34 at 180-degree intervals, facing radially outward, on the radially outer side of the one end 23a of the operating rod 23. 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 laser-engraved 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. In addition, curved lines 38 are engraved at predetermined intervals in a clockwise direction from each triangular mark 37, and the word "ON" is engraved outside the curved lines 38.

The positioning device described above, as shown in FIGS. 1A to 2B, operates as follows.
1A to 1C, in the initial state (release state) of the positioning device, 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 engages 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.

An operator carries 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. The workpiece 40 is then placed on the mounting base 42 on the table T.

To switch the positioning device from the released state to the locked state, the operator rotates the tool 43 inserted into the hexagonal hole 34 of the operating rod 23 clockwise. The clamp rod 7 is then engaged with the portion 39 of the operating rod 23 (the large-diameter portion of the operating rod 23) radially spaced from the axis of the operating rod 23 due to the biasing force of the lock spring 18, and is inserted across the stepped portion 44 formed approximately radially on the operating rod 23 into the insertion portion 45 (the small-diameter portion relative to the large-diameter portion of the operating rod 23). This causes the pressing member 11 to descend along the wedge surface 16 of the housing 1, expanding radially outward. When the outer circumferential surface of the pressing member 11 engages with the inner circumferential surface of the hole 41 in the workpiece 40, the descent of the clamp rod 7 is stopped. This switches the positioning device from the released state to the locked state. As a result, the positioning device positions the workpiece 40 at a predetermined position on the table T. When the positioning device is locked, 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 locked.

To switch 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 locking 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.

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 move 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.

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.

In the positioning device of the first modified embodiment shown in Figure 3A, only one cam portion 25 is 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 required to rotate the operating rod 23.

In the above-described positioning device, no sliding hole 29 is formed in the housing 1, and no locking member 30 or advancement spring 31 is provided. Furthermore, no recess 33 is provided on the outer peripheral wall of the operating rod 23. In a first variant of this embodiment, a recess 46 is formed in the cam portion 25, and a protrusion 47 that can be inserted 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 at 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 that opens 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 protrusion 47 of the clamp rod 7, and the downward biasing force of the lock spring 18 causes the protrusion 47 to insert 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.

The peripheral wall of the recess 46 is inclined so that the peripheral wall on the clockwise side, viewed from the bottom position where the recess 46 is deepest, forms an acute angle with respect to the radial direction compared to the peripheral wall on the counterclockwise side. In Figure 3A, the right wall of the recess 46 is inclined by α° with respect to the radial direction, while the left wall of the recess 46 is inclined by β° with respect to the radial direction. α° < β°. Therefore, when turning the operating rod 23 clockwise, it is possible to overcome the peripheral wall of the recess 46 with a relatively small force, but when an operator attempts to turn the operating rod 23 counterclockwise, it feels more difficult to turn than clockwise. This prevents the operator from turning the operating rod 23 in the wrong direction.

In the positioning device of the second modified embodiment shown in Figure 3B, four of the cam portions 25 are 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 approximately 90 degrees, a smaller angle than the positioning device of the above embodiment.

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. Furthermore, 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.

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

Claims (3)

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. 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). 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).