JPS591545B2 - Tool gripping device in automatic tool changer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tool gripping device in an automatic tool changer.

Generally, in machine tools, many types of machining tools are stored in a specified magazine attached to the machine body, and the tools are taken out as appropriate depending on the workpiece, and at the same time they are installed in the machine body. The machining tools installed on the main body side are stored in the magazine, and the machining tools in both the magazine and the machine body side are exchanged at °C. Conventionally, this machining tool exchange was carried out as shown in Figure 1. The test was carried out using tool gripping device a at °C.

In other words, in the same figure, 1 is the machine body (not shown)
2 is an arm whose center portion is attached and fixed to the tip of the arm shaft 1, and 3 and 3 are openable and closable tool gripping claws attached to both ends of the arm 20. The gripping claws 3, 3 are composed of a fixed claw 4 having an arc-shaped inner peripheral edge and an opening/closing claw 5, and can be opened in the same circumferential direction.

6 is a cylinder chamber formed at the center of the tip portion 1' of the arm shaft 1; 7 is a cylinder wall; 8 is a piston slidably inserted into the cylinder chamber 6; 9 is the arm shaft 1;
A member that is fitted into the tip part 1' and is rotatably fixed.
The arm shaft 1 is rotatable relative to this member 9.

Reference numerals 10 and 11 are oil supply and drainage holes communicating with a solenoid pulp (not shown), which are bored in the cylinder wall 7 at the tip of the arm shaft and are provided on both sides of the piston 80 with a temperature of °C.
holes 10a and 11a communicating with the cylinder chamber 6, respectively, and an annular groove 10b bored in the member 9 and formed in its inner circumferential wall.

A hole 10 that communicates with the holes 10a and 11a through 11b.
It consists of C and Ilc.

12 is a piston rod, 13 is this piston rod 12
It is a member that is attached and fixed to the tip of the cam and has a cam surface 14 that is inclined on the outer circumferential surface.

15 and 15 are a pair of sliding members each having a cam surface 16 that slides into contact with the cam surface 14 of the member 13, and 17 and 17 are the sliding members 15 and 15 and the opening/closing claws 5 of the tool gripping claws 3 and 3, respectively.
It is a connecting rod that connects the

Reference numeral 18 denotes a machining tool which is replaced as appropriate depending on the workpiece in the tool gripping device a having the above-mentioned configuration, and even if this machining tool is formed with an annular groove 19 which is gripped by the gripping claws 3, 3, Ru.

Many types of processing tools 18 are stored in a magazine attached to the machine body, and one of them is held by one of the gripping claws 3, and at the same time, the other gripping claw 3 is used to machine the machine. When a processing tool attached to the main body side is gripped and the husband's tool is gripped by both gripping claws 3, 3, the arm shaft 1 moves outward and then rotates to exchange the tool.

That is, to explain the operation of the conventional device a in more detail, first, the processing tool 18 is held by the gripping claws 3, 3 at both ends of the arm 2.
When gripping with , leave the arm shaft 1 retracted and operate the solenoid valve to open the oil supply/drain hole 1.
0 to the cylinder 70 chamber Ia side and move the piston 8 to the chamber 7b side, the sliding member 1
5.15 is positioned inward to hold the gripping claws 3, 3 in an open state.

In this state, when the arm shaft 1 is rotated until the tool gripping claws 3, 3 at both ends reach respective tool clamping positions on the magazine side and the machine body side, which are symmetrical positions on both sides of the arm shaft 10, the gripping claws 3, 3 each processing tool 18
into which the annular groove 19 fits.

After that, oil is supplied to the cylinder 7 through the oil supply and drain hole 11.
The piston 8 is moved to the chamber 7a side, and the cam mechanism of the member 13 and the sliding member 15.15 moves the sliding member 15.15 to the outside, respectively, and the connecting rod 17. The opening/closing claws 5 of the gripping claws 3, 3 are closed via 17 to securely grip the tool 18.

When the gripping operation of the tool is completed, the arm shaft 1 is moved outward (in the direction of the arrow shown in the figure) by an appropriate hydraulic cylinder (not shown), and then the arm 2 is moved 180 degrees in a predetermined direction around the arm shaft 1. As it rotates, the gripping claws 3, 3 at both ends are stopped at the opposite clamping positions, and then the arm shaft 1 is retracted by the appropriate hydraulic cylinder, thereby causing the magazine side to have a temperature of °C. The machining tool 18 gripped at a temperature is mounted on the machine body side, and the machining tool 18 gripped at a temperature at the machine body side is stored in a magazine side.

Then, the oil is again supplied to the cylinder chamber 70 via the oil supply/drainage hole 10.
It flows into the chamber Ib side, thereby causing the sliding member 15.15 to move inward in the same manner as described above, opening the gripping claws 3, 3, and releasing the grip on the machining tool 18.

When the grip on the machining tool is released in this way, the arm 2 rotates around the arm shaft 1 in the opposite direction to the above direction and is stopped at a predetermined position, waiting until the next tool change. .

However, according to the tool gripping device a having the above configuration, the tool grip 3 is attached to the rotating portion of the tip portion 1' of the arm shaft 1.
, 3 is equipped with a hydraulic cylinder to open and close.
Therefore, the oil supply structure becomes extremely complicated.

Moreover, a solenoid valve is required for hydraulic operation, and an electric circuit and hydraulic piping are required to control this solenoid valve, which not only complicates the structure but also increases the number of parts and costs. (.

Furthermore, since the conventional device a has a structure consisting of three elements: hydraulic, mechanical, and electrical, it is more likely to fail.

In view of the above-mentioned drawbacks, the present invention is an improvement on the above-mentioned drawbacks.
It is an object of the present invention to provide a tool gripping device for an automatic tool changer having a simple structure, low cost, and less failure.

The configuration of the present invention will be explained below based on the embodiments shown in the drawings.

In FIGS. 2 to 6, b indicates the tool gripping device of the present invention, 21 is an arm shaft attached to the machine body 22 so that it can move forward and backward and rotate, and 23 indicates the central part. An arm 24 of a predetermined length is attached and fixed to the distal end surface of the arm shaft 21. Reference numeral 24 indicates tool gripping claws provided at both ends of this arm 23. An arc-shaped fixed claw 25 and this fixed claw 2
An arc-shaped inner peripheral edge 27 pivotally connected to the base of 50 with a pin 26
The opening/closing pawl 27 has an opening/closing claw 27 having an opening/closing pawl 27 having a diameter of 1.

Reference numeral 28 denotes a push rod slidably inserted into a hole 29 bored in the center of the tip portion 21' of the arm shaft 21, which has a clamp portion 30 on the outer end side and a small diameter hole on the inner end side. It has a section 31.

32 is a stepped portion 33 of the hole 29 and a flange portion 3 of the push rod 28;
A spring 32 is compressed and installed in the hole 29 between the two holes, and the spring 32 constantly applies an outward biasing force to the push rod 28.

34.34 is a link mechanism interposed between the push rod 28 and the opening/closing claw 27 of each tool gripping claw 24.24; The pivots 36 and 36 installed in between are links that are offset from the center line in the longitudinal direction of the arm 23 and pivoted to the pivot shaft 35°35, respectively.
An equalizer 37 is rotatably installed between the inner end portions of the 6.degree. 36, and the tip end surface of the push rod 28 is always brought into contact with the lower surface of the center of the equalizer 37 by the spring force of the spring 32.

38 and 38 are guide members fixed to the bottom wall 23b of the arm 23, and 39 and 39 are slide members guided by the guide members 38 and 38, respectively, and slidably supported along the arm bottom wall 23b. , 40, 40 is the above link 36
．． 36 and slide member 39. :1, respectively, and its both ends are pivotally connected to each link 36, 36 and slide members 39, 39 with pivot pins 41, 41, 42, 42.

Reference numerals 43 and 43 refer to adjustment bolts screwed onto the outer end surfaces of the respective slide members 39, 39, and reference numerals 44 and 44 refer to the adjustment bolts screwed onto the outer end surfaces of the slide members 39, 39;
8. Hole 46 of each member 45.45 fixed between 38,
A compression spring is installed inside the opening/closing claw 27, 270 and interposed between the tips of the opening/closing claws 27, 270, and the tension of the springs 44, 44 always acts on the opening/closing claws 27, 27 in the closing direction.

Then, the push rod 28 is moved outward by the spring force of the spring 32, and the slide members 39, 39 are pushed outward via the respective link mechanisms 34, 34, thereby closing the opening/closing claws 27, 27. When the tool is clamped by the gripping claws 24, 24, the links 36, 36, relay links 40, 40, and slide members 39, 39 are connected to each other by pivot shafts 35, 35 and pivot pins 41, 41°. 42
．． 42 are arranged in a straight line and located at the dead point position.

Reference numeral 47.47 is a release rod that is supported through a predetermined portion of the arm bottom wall 23b, and is slidably guided by guide bushes 48, 48 that are fixedly attached to the bottom wall 23b.
Its inner end surfaces are brought into contact with rollers 49, 49 which are pivotally supported on one ends of the pivot pins 41, 41, respectively, and its spherical outer end portions are made to protrude to the outside of the arm 23.

Reference numeral 50 denotes an annular arm shaft guide member fixed to the opening of the arm shaft attachment hole 51 of the machine body 22;
Reference numeral 2 denotes a stopper member fixed to the outer end surface of this guide member 50, and a tapered surface 5 is provided at the inner peripheral edge of the outer end of the through hole 53.
An annular protrusion 55 having a diameter of 4 is formed.

Reference numeral 56 denotes a ring-shaped abutting member that is fitted and fixed to the stopper member 52 and has a flange portion 57 on the outer end side, and the outer end protruding portions of the release rods 47, 47 are attached to the flange portion 57.
It was made so that it was in contact with ℃・ru.

58, 58 are the tip portions 21' of the arm shaft 21;
This is a cutout hole drilled in a predetermined symmetrical part of the hole 2.
9 and in the holes 58 and 58 there are spheres 59 and 58, respectively.
59 is inserted.

Then, when the arm shaft 21 is retracted into the mounting hole 51 and is heated, each sphere 59.
The push rod 2 is retracted into the hole 29 against the spring force of 2.
8, and the arm shaft 21 is in contact with the outer peripheral surface of the mounting hole 5.
1, the push rod 28 is moved outward by the spring force of the spring 32 in connection with this movement, and is pushed into the notch holes 58 by the annular protrusion 55 of the stopper member 52. If the push rod 28 comes into contact with the small diameter portion 31 of the push rod 28, and if the push rod 28 is prevented from moving outward due to foreign matter, etc., the push rod 28 will not be pushed into the hole 29 and will be caught on the annular protrusion 55 of the stopper member 52. It functions as a safety device that prevents the arm shaft 21 from moving.

Reference numeral 60 denotes a machining tool that is replaced as appropriate depending on the workpiece in the tool gripping device, and this machining tool 60 includes the gripping claws 24.
．． An annular groove 61 is formed to be gripped at 24.

Reference numeral 62 denotes a tool 6 fixed to the fixed claw 250 at a predetermined position.
0 rotation stopping member.

The operation of the apparatus having the above configuration will be explained as follows.

First, when unclamping the processing tool 60, the arm shaft 21 is retracted into the mounting hole 51 of the machine body 22, as shown in FIG. 2, and the arm 23 is brought to a predetermined position.

At this time, the outer end protruding portion of each release rod 47, 47 presses against the flange portion 57 of the abutment member 56, and the release rod 47, 47
is pushed into the arm 23 against the biasing force of the spring 32, and the rollers 49, 49 at one end of the pivot pins 41, 41 in each of the link mechanisms 34, 34 are pressed.

As a result, each link 36, 36 has a pivot axis of 35°35.
The push rod 28 rotates inward using the fulcrum as a fulcrum, and the push rod 28 retreats into the hole 29 against the biasing force of the spring 32 via the equalizer 37 provided as a bridge between its inner ends, and the slide members 39, 3
9 slides inwardly along the arm bottom wall 23b, and the opening/closing claws 27° 27 of the gripping claws 24, 24, which are pressed by the adjustment poles 43 and 43, are held in the open state, and at the same time, the notch holes 58 The spheres 59, 59 fitted in ゜58 are push rods 28
When it comes into contact with the outer circumferential surface of

Then, the tool clamp position on the side of the magazine (not shown) that is attached to the machine body 22 and accommodates many types of processing tools, and the machine body 22 at a position symmetrical to the tool clamp position with the arm shaft 21 as the center. Each processing tool 6 located at the side tool clamp position (tool mounting position)
0, press the release rods 47, 47 on the member 56.
While holding the gripping claws 24, 24 in an open state, the arm shaft 21 is rotated until the gripping claws 24, 24 reach the tool clamping position, respectively. 24, 24 into the annular groove 6 of the tool 60
Insert into 1.

At this time, the opening/closing claws 27.27 are compressed by the compression springs 44, 4.
Grip the tool 60 with a force of 40 °C.

Then, at the same time that the gripping claws 24 and 24 fit into this annular groove 61, the arm shaft 21 is moved outward.

Along with this movement of the arm shaft 21, the abutment member 5
The pressure of the release rod 47.47 against the flange portion 57 of 6 is gradually released, and as a result, the push rod 28
Equalizer 3 is moved outward by the spring force of 2.
7, the links 36 and 36 rotate outward about the pivots 35 and 35, and due to this link action, the release rods 47 and 47 are pressed by the rollers 49 and 49, and the arms 1
At the same time, the slide member 3 is moved outwardly.
9°39 slides outward along the arm bottom wall 23b,
The opening/closing claw 27.27 is pressed by the adjustment pole) 43.43,
The pivot shafts 35, 35 and the pivot pins 41, 41, 42, 42 of each link mechanism 34, 34 are aligned in a straight line and are located at the dead point position, and the gripping claws 24, 24 are attached to each tool 6.
0 from the tapered hole for holding tools on the magazine side and the machine body side.

In connection with the movement of the arm shaft 21 and the push rod 28, the arm shaft 21 and the push rod 28 are fitted into the notch holes 58° and 58°C.
Each sphere 59.59 is pushed into the hole 29 by the tapered surface 54 of the protrusion 55 of the stopper member 52, and the push rod 28
The arm shaft 21 contacts the outer circumferential surface of the small diameter portion 31 of the
moves smoothly.

In this way, when each tool 60 is gripped by the gripping claws 24 and 24 in connection with the movement of the arm shaft 21 toward the outside, the arm shaft 21 rotates 180 degrees in a predetermined direction, and grips both ends of the arm 230. After the pawls 24, 24 are respectively brought to a stop position in their symmetrical tool clamping positions,
The arm shaft 21 is retracted into the mounting hole 51.

With this retracting operation, the release rods 47, 47 are pressed against the contact member 5.
As a result, the push rod 28 is pushed into the arm 23 by the flange portion 57 of 6, and the push rod 28 is moved into the hole 29 through each link mechanism 34, 34 against the biasing force of the spring 32, and the small diameter The spheres 59, 59 which are in contact with the part 31 and are heated to a temperature of 0.degree. (Move to Adjust Port) 43.
The opening/closing claws 27, 27, which are pressed by 43 and held at ℃, are held by the tension of compression springs 44 and 440, and the grips on each tool 60 are released, and the machining tools 60 held at ℃ on the magazine side are The machining tool 60 held on the machine body side or on the machine body side is accommodated and held in each tool holding taper hole on the magazine side, and the replacement of the tool 60 is completed.

When each processing tool 60 is released from the gripping claws 24.degree. 24, the arm shaft 21 rotates by a predetermined angle.

At this time, the opening/closing claws 27, 27 are opened by the tool 60 in contact with the force of the compression springs 44, 44.

This rotation of the arm shaft 21 causes the arm 23 to stop at a predetermined position.

Repeat the same operation below.

During the above operation, if the push rod 28 is prevented from moving outward due to foreign matter, etc., the balls 59, 59 fitted in the notch holes 58, 58 will move toward the small diameter portion 31 side of the push rod 28. Therefore, when the arm shaft 21 advances, each of the spheres 59 and 59 touches the annular protrusion 5 of the stopper member 52.
5, the movement of the arm shaft 21 is blocked, the device automatically stops, and the operator is notified of the malfunction.

As described above, since the present invention is equipped with a safety device, even if a failure should occur, it can be detected quickly.

As explained above, the present invention has one end fixed to the rotation center position of an arm equipped with a tool gripping claw consisting of a fixed claw and an opening/closing claw at both ends, so that it can move forward and backward in the axial direction of the machine body and can rotate. It is fitted into the attached arm shaft and the axial hole in the center of the above-mentioned end of the arm shaft so that it can move forward and backward,
A push rod has a small diameter portion at its rear end and is always pressed forward in the forward direction by a spring, and a push rod whose center portion is pivotably pivoted to the arm at a position equidistant from the center of rotation of the arm, and one end of which is pivoted to the arm. It consists of a pair of links that are brought into contact with each other, and a relay link that connects both ends between the other end of the pair of links and a slide member that controls the opening and closing of the opening/closing claws at both ends of the arm. The opening/closing link mechanism of the opening/closing pawl, which self-locks the opening/closing pawl in the closed state through a slide member, with the pivot point of the link and the connection points at both ends of the relay link aligned in a straight line, and the connecting point position of the relay link. A lock release rod is provided on the arm so that it can move forward and backward in parallel with the push rod, and a lock release rod is fixed to the machine body in correspondence with the lock release rod. an abutting member for releasing the lock; a sphere provided so as to be able to protrude and retract in the radial direction of the arm shaft in correspondence with the push rod; Since the tool gripping device is constituted by a stopper member that controls the forward and backward movement of the push rod by *+m, the tool gripping claw can be mechanically controlled to open and close by simply moving the arm shaft forward and backward.

In particular, by making the arm shaft's protruding action the tool pulling action from the tool magazine and the machine body, and its retracting action the tool mounting action, when the arm shaft protrudes, the release bar becomes free, and the push bar allows the link mechanism to Since the dead point is in a straight line and the tool gripping state self-locks, the tool does not fall off when the arm turns, making it safe.

In addition, the grip of the tool is incomplete.

When the push rod does not protrude and the sphere remains protruding outward, when the arm shaft attempts to protrude, the sphere is locked by the stopper member and prevents the arm shaft from protruding, making it difficult to grip the tool. It is safe because the automatic tool exchange operation will not be performed if the tool is incomplete.

Furthermore, the structure is simple and inexpensive.

[Brief explanation of drawings]

FIG. 1 is a partially sectional explanatory diagram showing a conventional tool gripping device. 2 is a side sectional view of the tool gripping device according to the present invention, FIG. 3 is a partial plan sectional view of FIG. 2, FIG. 4 is a side sectional view showing the operating state of FIG. 2, and FIG. 6 is a sectional plan view thereof, and FIG. 6 is a sectional view of a part thereof taken along line A--A in FIG. 5. 21... Arm shaft, 21'...
Tip part, 22...Machine body, 23...
・Arm, 24, 24... Tool gripping pressure, 25・
...Push rod, 34.34...Link mechanism,
35.35...Axis, 41,41°42.42
...... Pivot Hin.

Claims (1)

[Claims] 1. An arm shaft with one end fixed to the rotation center position of an arm equipped with a tool gripping claw consisting of a fixed claw and an opening/closing claw at both ends, and attached to the machine body so that it can move forward and backward in the axial direction and rotate, and the arm shaft. A push rod is fitted into the central axial hole at one end of the arm so as to be movable forward and backward, has a small diameter section at the rear end, and is constantly pushed forward in the forward direction by a spring. A pair of links whose central part is pivotably attached to the arm, one end of which is in contact with a push rod, and the other end of the pair of links and a slide member that controls the opening and closing of the opening/closing claws at both ends of the arm. It is composed of a relay link whose both ends are connected, and by the protruding action of the push rod, the pivot point of the pair of links and the connection point of both ends of the relay link are aligned in a straight line, and the opening/closing claw is self-locked in the closed state via the sliding member. The opening/closing link mechanism of the opening/closing claw, the lock release bar provided on the arm at the connection point between the relay link and the pair of links so that it can move forward and backward parallel to the push bar, and the lock release bar fixed to the machine body in correspondence with the lock release bar. a contact member which is provided and which releases the self-lock of the link by abutting against the lock release rod at the retracted end position of the arm shaft; a sphere provided so as to be retractable in the radial direction of the arm shaft corresponding to the push rod; A tool gripping device in an automatic tool changer, comprising a stopper member fixedly attached to a machine body corresponding to a sphere and controlling the protrusion and retraction of the sphere and controlling the forward and backward movement of a push rod when an arm shaft moves forward and backward.