JP7420592B2 - tool changer - Google Patents

Description

The present invention relates to a tool changing device.

Tool changing devices have been developed to change tools on the spindle of machine tools. The tool changer includes an arm that grips a tool, and a lock mechanism that locks and unlocks the gripped tool.

A locking mechanism is installed within the arm. A locking mechanism often includes a link that is operated by an external force and an elastic member (eg, a spring) that returns the link when no external force is applied. When this locking mechanism operates, the volume inside the arm changes and outside air may be drawn in (for example, when the tool is locked, the components of the locking mechanism move in the direction of protruding outside the arm, causing (volume increases, creating negative pressure).

Here, a mist of cutting fluid (mist) is often generated when a machine tool operates. This mist floats near the arm or adheres to the arm. Therefore, when the lock mechanism is operated, there is a possibility that mist may enter the arm together with the outside air. Mist in the arm can cause poor lubrication of the locking mechanism and even damage it. That is, it is undesirable for foreign matter (for example, mist) to enter the arm.

Japanese Patent Application Publication No. 2016-043466

SUMMARY OF THE INVENTION An object of the present invention is to provide a tool changing device that reduces the intrusion of foreign objects into an arm.

A tool changer according to an embodiment includes a housing in which a first internal space is formed, a gripping part for gripping a tool, an arm in which a second internal space is formed, and the gripping part. a locking member for pressing a tool gripped by the arm; an arm shaft connected to the arm; a cam mechanism arranged in the first internal space for rotating or raising/lowering the arm shaft; a locking mechanism disposed within the internal space of the locking member for moving the locking member. The housing has a first communication hole that communicates the first internal space with the outside, and the arm shaft has a second communication hole that communicates the first internal space and the second internal space. Has holes.

According to the present invention, it is possible to provide a tool changing device that reduces the intrusion of foreign objects into the arm.

FIG. 1 is a diagram illustrating a tool changing device according to an embodiment. FIG. 3 is a perspective view of an arm according to an embodiment. FIG. 3 is an exploded perspective view showing a state in which the arm shaft and the arm are separated. FIG. 2 is a cross-sectional view of the arm shaft and the arm taken along IV-IV in FIG. 1, showing a connection state between the arm shaft and the arm.

A tool changing device according to an embodiment will be described in detail below with reference to the drawings. FIG. 1 shows a tool changing device 10 according to an embodiment. The tool changer 10 includes a housing 11 , a motor 13 , a speed reduction mechanism 14 , a cam 17 , a link 18 , an arm shaft 21 , a cylindrical body 22 , a rotation engagement portion 23 , an elevation engagement portion 26 , and an arm 30 . Among these, the cam 17, the link 18, the rotation engagement part 23, and the elevation engagement part 26 constitute a cam mechanism that raises, lowers, and rotates the arm shaft 21.

The housing 11 has an internal space 11a (first internal space) and a communication hole 11b (first communication hole). In order to maintain the lubricity of the cam mechanism, the internal space 11a contains a liquid lubricant L. As a result, the internal space 11a can be divided into a lubricant region filled with the lubricant L and an atmospheric region filled with the atmosphere above the lubricant region (which may include components of the vaporized lubricant L). However, the boundaries of these regions vary depending on the amount of lubricant L injected or consumed. The communication hole 11b opens to the atmospheric region, allows the internal space 11a (atmospheric region) to communicate with the outside (atmosphere), and allows the atmospheric air to circulate.

The motor 13 is attached to the outside of the housing 11 and supplies rotational force into the housing 11 . The deceleration mechanism 14 decelerates the rotational speed output from the motor 13 to an appropriate value. Note that as an example of the speed reduction mechanism 14, a combination of a worm gear and a worm wheel can be used, but the present invention is not limited thereto, and various speed reduction mechanisms (eg, gears) can be used.

The cam 17 is rotated about the rotation axis O by the motor 13 via the speed reduction mechanism 14 . In this example, the rotation axis O is perpendicular to the axis of the motor 13, but it may be parallel to it. The cam 17 has a substantially cylindrical shape, and has a groove 17a formed on its end surface and a groove 17b (not shown) formed on its circumferential surface. The groove 17a can be divided into sections A1 to A4. The groove 17a has a substantially arc shape in the sections A1 and A3, and has a substantially linear shape in the sections A2 and A4. The groove 17b is divided into sections B1 to B4 corresponding to the sections A1 to A4 of the groove 17a. The groove 17b is substantially parallel to the circumference of the cam 17 in sections B2 and B4, and is inclined with respect to the circumference of the cam 17 in sections B1 and B2.

The link 18 has a link body 18a, a fulcrum 18b, a protrusion 18c, and a protrusion 18d. The link body 18a has an overall rod shape or an elongated plate shape. The fulcrum 18b is arranged at one end of the link body 18a and is rotatably fixed to the housing 11. That is, the link 18 can rotate around this fulcrum 18b. The protrusion 18c is inserted into (engaged with) the groove 17a of the cam 17. The protrusion 18d is disposed at the other end of the link body 18a and engages with the vertical engagement portion 26.

The arm shaft 21 has a substantially cylindrical shape and has an axial hole 21a, a through hole 21b, and a through hole 21c (first through hole). The axial hole 21a extends in the axial direction of the arm shaft 21. The through holes 21b and 21c are arranged above and below the axial hole 21a, and penetrate between the axial hole 21a and the side surface. The axial hole 21a and the through holes 21b and 21c connect the internal space 11a (first internal space) of the housing 11 and the internal space 31b (second internal space) of the arm 30, which will be described later, and allow the lubricant L to It functions as a flow path (second communication hole) for the circulating lubricant L. A cylindrical body 22 and a rotational engagement part 23 are arranged at the upper part of the arm shaft 21, and an elevation engagement part 26 (guide ring) is arranged at the lower part.

The upper end of the cylindrical body 22 is rotatably supported relative to the housing 11 . The cylindrical body 22 has a substantially cylindrical shape and holds the upper part of the arm shaft 21 therein. The arm shaft 21 rotates integrally with the cylindrical body 22 and is engaged with the cylindrical body 22 so that it can be moved up and down relative to the cylindrical body 22.

The rotational engagement portion 23 has a generally ring shape with a concave cross section, is fixed to the outer periphery of the cylindrical body 22 near the lower end, and is rotatable together with the cylindrical body 22 . The rotational engagement portion 23 has an engagement protrusion 23a that engages with the groove 17b.

The elevating engaging portion 26 has a substantially ring shape, is fixed to the outer periphery of the arm shaft 21, and engages with the protruding portion 18d of the link 18.

Here, the movement of the arm shaft 21 when the motor 13 operates will be explained. As shown below, when the motor 13 operates, the arm shaft 21 alternately moves up and down and rotates.

First, the protrusion 18c of the link 18 is arranged near the boundary between section A1 and section A4 of the groove 17a of the cam 17, and the engagement protrusion 23a of the rotational engagement section 23 is arranged at the boundary between section B1 and section B4 of the groove 17b. Suppose it is placed nearby. As the motor 13 operates and the cam 17 rotates, the protrusion 18c of the link 18 sequentially moves through sections A1, A2, A3, and A4 of the groove 17a, and the engagement protrusion 23a of the rotational engagement part 23 It is assumed that sections B1, B2, B3, and B4 of the groove 17b are moved in order.

When the protrusion 18c moves within the section A1 of the groove 17a and the engagement protrusion 23a moves within the section B1 of the groove 17b, the arm shaft 21 rotates without moving up and down. This can be explained as follows. That is, the groove 17b is inclined with respect to the circumference of the cam 17 in the section B1. Therefore, the engagement protrusion 23a moves in the axial direction of the cam 17 when moving in the section B1, and rotates the rotary engagement part 23. When the rotational engagement portion 23 rotates, the cylindrical body 22 and, by extension, the arm shaft 21 rotate. On the other hand, the groove 17a has a substantially arc shape centered on the rotation axis O in the section A1. Therefore, when the protrusion 18c moves within the section A1, the distance from the rotation axis O is kept constant, so that the protrusion 18c does not substantially move up and down, and the link 18 does not rotate. As a result, the protrusion 18d of the link 18, and by extension the elevating engagement portion 26 and the arm shaft 21, do not move up or down.

When the protrusion 18c moves within the section A2 of the groove 17a and the engagement protrusion 23a moves within the section B2 of the groove 17b, the arm shaft 21 moves up and down without rotating. This can be explained as follows. That is, when moving in the section A2, the projection 18c moves up and down (here, descends) as the distance from the rotation axis O changes, and the link 18 rotates. As a result, the protrusion 18d of the link 18, as well as the elevating engagement portion 26 and the arm shaft 21, move up and down. On the other hand, the groove 17b is parallel to the circumference of the cam 17 in section B2. Therefore, the engagement protrusion 23a does not move in the axial direction of the cam 17 when moving in the section B2, and does not rotate the rotary engagement part 23. Since the rotational engagement portion 23 does not rotate, the cylindrical body 22 and the arm shaft 21 also do not rotate.

Similarly, when the protrusion 18c moves within the section A3 of the groove 17a and the engagement protrusion 23a moves within the section B3 of the groove 17b, the arm shaft 21 rotates without moving up and down. Further, when the protrusion 18c moves within the section A4 of the groove 17a and the engagement protrusion 23a moves within the section B4 of the groove 17b, the arm shaft 21 does not rotate but moves up and down (in this case, rises). In this way, when the motor 13 is moved, the arm shaft 21 sequentially rotates, descends, rotates, and rises.

Next, details of the arm 30 will be explained. FIG. 2 is a perspective view of the arm 30 fixed to the arm shaft 21. FIG. 3 is an exploded perspective view showing a state in which the arm shaft 21 and the arm 30 are separated. FIG. 4 is a cross-sectional view of the arm shaft 21 and the arm 30 taken along IV-IV in FIG. 1, and shows the connection state of the arm shaft 21 and the arm 30.

The arm 30 is connected to the lower end of the arm shaft 21 and moves up and down and rotates together with the arm shaft 21. The arm 30 has a substantially rectangular parallelepiped shape and includes an arm body 31, a grip portion 32, a lock member 33, a lock shaft 34, a link 35, a pressing member 36, and an elastic member 37. The arm 30 is a so-called double arm, and has a pair of gripping parts 32 and a pair of locking members 33.

The arm body 31 has a through hole 31a, an internal space 31b (second internal space), and a flow path 31c. The through hole 31a has a substantially cylindrical shape, and the arm shaft 21 is inserted and fixed therein.

The internal space 31b is a space for arranging the pressing member 36 and the elastic member 37. The internal space 31b is filled with a lubricant L to ensure smooth operation of the lock shaft 34, link 35, pressing member 36, elastic member 37, and the like. The upper side of the internal space 31b is sealed by a vertically movable pressing member 36.

The flow path 31c allows the through hole 21c of the arm shaft 21 and the internal space 31b of the arm body 31 to communicate with each other, and enables supply of the lubricant L from the internal space 11a of the housing 11 to the internal space 31b of the arm body 31. . One end side of the flow path 31c is connected to the internal space 31b. The other end side of the flow path 31c has an opening 31d that opens into the through hole 31a of the arm body 31. That is, the internal space 31b of the arm body 31 communicates with the through hole 21c (further, the axial hole 21a, the through hole 21b, and the internal space 11a) of the arm shaft 21 via the flow path 31c and the opening 31d.

However, as shown in FIGS. 3 and 4, the lower end of the axial hole 21a of the arm shaft 21 is opened, and the opening/closing member 41 is inserted therein to open and close the through hole 21c. Note that the details will be described later.

The grip part 32 grips a tool. The locking member 33 locks the tool gripped by the gripping portion 32. The lock member 33 is connected to a pressing member 36 by a lock shaft 34 and a link 35.

One end of the lock shaft 34 is connected to the lock member 33. The other end of the lock shaft 34 is rotatably connected to one end of the link 35.

The link 35 is rotatably connected to other members by rotation axes O1 to O3. The rotation axis O1 is arranged at the center of the link 35, and rotatably connects the link 35 to the arm body 31. The rotation axis O2 is arranged at one end of the link 35, and rotatably connects the link 35 to the pressing member 36. The rotation axis O3 is arranged on the other end side of the link 35, and rotatably connects the link 35 to one end of the lock shaft 34.

The pressing member 36 is divided into a sealing part 361, a protruding part 362, and a main body part 363, and is displaced downward when pressed. The sealing part 361 seals the internal space 31b and prevents the lubricant L from leaking from the internal space 31b. The protrusion 362 protrudes from the arm body 31. By pressing the protrusion 362 from above, the pressing member 36 is displaced downward. The main body portion 363 is connected to the link 35 by the rotation axis O2. The elastic member 37 urges the pressing member 36 upward.

The link 35, the pressing member 36, and the elastic member 37 move the locking member 33 as follows.

When the pressing member 36 (protrusion 362) is pressed, the pressing member 36 is displaced downward, lowering the rotation axis O2 of the link 35. The link 35 rotates around the rotation axis O1 and moves the rotation axis O3 (lock shaft 34, lock member 33) in the direction toward the arm shaft 21. As a result, the lock member 33 unlocks the tool held by the grip portion 32 (unlocks).

When the pressing member 36 is stopped, the pressing member 36 returns upward due to the urging force of the elastic member 37, and the locking member 33 locks the tool gripped by the gripping portion 32.

The tool is unlocked and locked by applying and stopping pressure to the pressing member 36. The link 35 and the elastic member 37 function as a locking mechanism that moves the locking member 33.

When the lock mechanism operates, the pressing member 36 (sealing portion 361) that seals the internal space 31b is displaced up and down, and the volume (and thus the internal pressure) of the internal space 31b changes. For example, when the tool is locked, both the pressing member 36 and the lock shaft 34 move in the direction of protruding outside the arm 30 due to the biasing force of the elastic member 37, thereby increasing the volume of the internal space 31b and increasing the volume of the internal space 31b (inner space A negative pressure is created at 31b). Such a change in volume (internal pressure) may cause outside air to flow into the internal space 31b through the gap between the lock shaft 34 and the arm body 31, etc. As a result, foreign matter (mist, etc.) may enter the internal space 31b of the arm 30, leading to poor lubrication of the locking mechanism and, ultimately, damage to the locking mechanism.

However, in this embodiment, the internal space 31b of the arm 30 communicates with the internal space 11a of the housing 11 having the communication hole 11b (air bleed duct). Therefore, a change in the volume of the internal space 31b is absorbed by the housing 11 side.

That is, as the volume of the internal space 31b changes, the lubricant L flows into and out of the internal space 11a of the housing 11 into the internal space 31b of the arm 30. As a result, an amount of lubricant L commensurate with the volume of the internal space 31b is always placed in the internal space 31b, and even if the volume of the internal space 31b changes, outside air or the like will not flow into the internal space 31b.

At this time, the change in the volume of the internal space 31b causes an increase or decrease in the amount of lubricant L in the internal space 11a, but this increase or decrease is absorbed by the intake and exhaust of the atmosphere from the communication hole 11b to the internal space 11a.

Even if this atmosphere contains mist, the amount of air intake and exhaust is very small considering the size of the internal space 11a (the amount of lubricant L), and the influence on the cam mechanism is extremely small. Further, by installing a filter for removing mist and the like contained in the atmosphere in the communication hole 11b, this influence can be further reduced. Alternatively, or in addition to this, a pipe extending from the communication hole 11b to the outside of the processing chamber (the room in which the tool changer 10 and the like are installed) may be used to prevent mist and the like from entering.

In this way, the internal space 11a of the housing 11 and the internal space 31b of the arm 30 are communicated through the axial hole 21a and the through holes 21b and 21c of the arm shaft 21, so that the lubricant L can flow therethrough. As a result, it is possible to prevent outside air from flowing into the internal space 31b, and also to supply the lubricant L for lubricating the cam 17 and the like to the arm 30. In this way, by preventing foreign objects from entering the internal space 31b and supplying the lubricant L to the internal space 31b, the life of the locking mechanism (link 35, elastic member 37) of the locking member 33 is extended. can be achieved.

As shown in FIGS. 3 and 4, an opening/closing member 41 and a cover 42 are arranged at the lower end of the arm shaft 21. As shown in FIGS.

The opening/closing member 41 has a bottomed cylindrical shape as a whole, has an opening/closing part main body 411 and a lid part 412, and opens and closes the through hole 21c (first through hole) of the arm shaft 21. The opening/closing part main body 411 has a substantially cylindrical shape and has an axial hole 41a and a pair of through holes 41b (second through holes). The through hole 41b passes through the inner periphery (axial hole 41a) and outer periphery of the opening/closing part main body 411. The opening/closing part main body 411 has an outer circumference corresponding to the inner circumference of the arm shaft 21 and is inserted into the inner circumference of the arm shaft 21 . The lid portion 412 has a substantially cylindrical shape and seals the lower end of the arm shaft 21.

Normally, the pair of through holes 41b are arranged to face the pair of through holes 21c of the arm shaft 21. In this case, the axial hole 21a and the through hole 21c of the arm shaft 21 are connected through the axial hole 41a and the through hole 41b of the opening/closing part main body 411. On the other hand, the opening/closing member 41 can be rotated relative to the arm shaft 21 so that the through hole 21c of the arm shaft 21 and the through hole 41b of the opening/closing part main body 411 do not face each other. At this time, the space between the axial hole 21a of the arm shaft 21 and the through hole 21c is closed by the outer circumferential surface of the opening/closing part main body 411.

In this way, by rotating the opening/closing member 41, communication and non-communication between the through hole 21c (first through hole) and the through hole 41b (second through hole) are switched, and the through hole 21c of the arm shaft 21 is switched between communication and non-communication. Can be opened and closed.

The cover 42 covers the lid part 412, but includes an opening 42a that exposes the bottom surface of the lid part 412. Therefore, with all the members of the arm 30 attached to the arm shaft 21, the bottom surface of the lid part 412 is accessed through the opening 42a of the cover 42, the opening/closing member 41 is rotated, and the through hole 21c of the arm shaft 21 is opened. Can be opened and closed. For example, a groove is formed on the bottom surface of the lid part 412, and a predetermined tool (for example, a screwdriver) can be engaged with this groove and rotated.

The opening/closing member 41 can be used when removing the arm 30 from the arm shaft 21. As mentioned above, the through hole 21c of the arm shaft 21 is normally open. If the arm 30 is removed from the arm shaft 21 in this state, the lubricant L inside the housing 11 may leak out from the through hole 21c. That is, before removing the arm 30 from the arm shaft 21, the opening/closing member 41 is rotated to close the through hole 21c, thereby preventing leakage of the lubricant L when the arm 30 is removed (during assembly or maintenance). After the through hole 21c is closed, the cover 42 is removed, and the arm 30 is further removed from the arm shaft 21.

[Technical idea obtained from the embodiment]
The technical ideas that can be understood from each of the above embodiments will be described below.

[1] The tool changer (10) according to the embodiment has a housing (11) in which a first internal space (11a) is formed, a gripping part (32) for gripping a tool, and a first an arm (30) in which a second internal space (31b) is formed; a locking member (33) for pressing a tool held by the gripping part (32); and a locking member (33) connected to the arm (30). An arm shaft (21) and a cam mechanism (cam 17, link 18, rotational engagement part 23, elevation engagement) that is arranged in the first internal space (11a) and rotates or raises and lowers the arm shaft (21). portion 26), and a locking mechanism (link 35, elastic member 37) that is disposed within the second internal space (31b) and moves the locking member (33). The housing (11) has a first communication hole (11b) that communicates the first interior space (11a) with the outside, and the arm shaft (21) has a first communication hole (11b) that communicates the first interior space (11a) with the outside. ) is provided with a second communication hole (axial hole 21a) that communicates with the second internal space (31b). Thereby, by communicating the first internal space (11a) and the second internal space (31b), it is possible to prevent foreign objects from entering the second internal space (31b), and to extend the length of the locking mechanism. It is possible to extend the service life.

[2] The atmosphere flows through the first communication hole (11b), and the lubricant (L) flows through the second communication hole (axial hole 21a). Thereby, an increase or decrease in the amount of lubricant (L) within the first internal space (11a) can be absorbed.

[3] The second communication hole (axial hole 21a) communicates with an axial hole (21a) formed along the axial direction of the arm shaft (21) and the axial hole (21a). , a first through hole (21c) that opens on the side surface of the arm shaft (21). The tool changer (10) further includes an opening/closing member (41) that opens and closes the first through hole (21c). Thereby, the first through hole (21c) can be closed by the opening/closing member (41), and leakage of the lubricant (L) when the arm (30) is removed can be prevented.

[4] The opening/closing member (41) has a bottomed cylindrical member (41) that is rotatably inserted into the axial hole (21a), and the cylindrical member (41) includes: A second through hole (41b) passing through the inside and outside is formed, and by rotating the cylindrical member (41), the first through hole (21c) and the second through hole (41b) can be connected. Communication and non-communication are switched. This facilitates opening and closing of the first through hole (21c).

10... Tool changer 11... Housing 11a, 31b... Internal space 11b... Communication hole 13... Motor 14... Reduction mechanism 17... Cam 18, 35... Link 21... Arm shaft 21a... Axial hole 21b, 21c, 31a, 41b ...Through hole 22...Cylindrical body 23...Rotating engagement part 26...Elevating engagement part 30...Arm 31...Arm body 31c...Flow path 31d, 42a...Opening 32...Gripping part 33...Lock member 34...Lock shaft 36... Pressing member 37...Elastic member 41...Opening/closing member 41a...Axial hole 42...Cover

Claims (3)

A casing in which a first internal space is formed;
an arm having a gripping portion for gripping a tool and forming a second interior space;
a locking member for pressing a tool held by the gripping portion;
an arm shaft connected to the arm;
a cam mechanism disposed in the first internal space that rotates or raises/lowers the arm shaft;
a locking mechanism disposed within the second internal space and configured to move the locking member;
The casing has a first communication hole that communicates the first internal space with the outside,
The arm shaft has a second communication hole that communicates the first internal space with the second internal space,
The first communication hole allows the atmosphere to circulate,
The second communication hole is a tool changing device through which a lubricant flows . The tool changing device according to claim 1 ,
The second communication hole is
an axial hole formed along the axial direction of the arm shaft;
a first through hole communicating with the axial hole and the second internal space and opening on a side surface of the arm shaft;
The tool changing device further includes an opening/closing member that opens and closes the first through hole. The tool changing device according to claim 2 ,
The opening/closing member has a bottomed cylindrical member rotatably inserted into the axial hole,
A second through hole is formed in the cylindrical member, passing through the inside and outside of the cylindrical member,
A tool changing device in which communication and non-communication between the first through hole and the second through hole are switched by rotating the cylindrical member.

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