KR102585456B1 - Automatic tool changer and machine tool including the same - Google Patents

Abstract

The gripper arm unit of the automatic tool changer moves the gripper unit forward or backward by a joining pin that is elastically supported from the lower end of the main guide shaft and has an inclined surface formed toward the gripper unit, and an inclined surface and a sliding action of the pressing pin. a gripper pin having an inclined surface formed at one end opposite to the inclined surface of the pressing pin, a lower end of the main guide shaft protruding below the pressing pin, and a link pin rotatable at one end of the gripper pin having the inclined surface so as to It consists of a link that transmits the forward or backward motion of the main guide shaft to the gripper pin.

Description

Automatic tool changer and machine tool including the same}

The present invention relates to an automatic tool changing device for a numerically controlled machine tool and a machine tool including the device, and more specifically, to firmly holding a tool in an automatic tool changing device.

In general, numerically controlled machine tools are equipped with an automatic tool changer to exchange tools between the spindle of the machine tool and the tool magazine.

More specifically, the automatic tool changer provides tools mounted on the tool magazine to the spindle according to commands from the NC device (numerical control device), or moves the tools mounted on the spindle to the tool magazine and installs them. .

In this type of tool change operation, the tool magazine provides tools to the spindle or stands by at a tool change position where it can receive tools provided from the spindle, and the spindle also accepts tools provided by the tool magazine or tools mounted on the spindle. Move to the tool change location where it can be sent to the tool magazine and wait.

In this way, with the tool magazine and the spindle standing by at the tool exchange position, the automatic tool change device operates to remove or install the tool between the spindle and the tool magazine to perform a tool exchange operation.

As one of the conventional automatic tool changing devices described above, Korean Patent No. 10-1796791 (referred to as Cited Invention 1) will be described with reference to FIGS. 1 and 2.

First, Figure 1 is a perspective view to explain the automatic tool changer of cited invention 1, and Figure 2 is a front view to explain the automatic tool changer of cited invention 1.

In the automatic tool changer 200 of cited invention 1, a fixed housing 210 is installed on one side of the cam box 102, and a main shaft 130 that performs rotational and linear movements is installed in this fixed housing 210. And a gripper arm unit 140 is installed at the end of the main shaft 130.

A cam unit 230 is installed at the end 212 of the fixed housing 210, and first and second cam surfaces 232 and 234 of different heights are formed on one side of the cam unit 230. do.

A first guide wheel 240 is installed on the outer diameter of the cam unit 230 to be rotatable by a bearing unit, and an installation hole is formed in the first guide wheel 240.

In addition, the main guide shaft 250 is disposed to penetrate the first guide wheel 240, and more specifically, its axis is arranged parallel to the main shaft 130.

Additionally, a bearing unit may be disposed in the installation hole, and the main guide shaft 250 may penetrate the bearing unit.

The bearing unit reduces linear movement resistance when the main guide shaft 250 moves in the axial direction.

In addition, a second guide wheel 260 is installed on the outer diameter of the fixed housing 210 in an idle state and spaced apart from the first guide wheel 240. The second guide wheel 260 is fixed to an end of the main guide shaft 250.

Additionally, a cam follower 236 is installed on the second guide wheel 260, and one side of the cam follower 236 slides on the first and second cam surfaces 232 and 234.

Meanwhile, a plurality of the first and second cam surfaces 232 and 234 and the cam follower 236 may be arranged to be rotationally symmetrical, and thus the first guide wheel 240 and the second guide wheel 260 is maintained in parallel, thereby reducing the resistance to linear movement of the main guide shaft 250 and maintaining a stable posture between the first and second guide wheels 240 and 260.

In addition, the gripper arm unit 140 is provided with gripper units 148 for storing tools T at both ends, and a gripper block 149 is installed in the gripper unit 148 to advance and retreat, and the gripper block ( 149) is a gripper pin 145, a link 144, and a pressure pin 143 are connected, a restoration spring 147 is disposed on the outside of the pressure pin 143, and a cap is placed on the outside of the restoration spring 147. (146a) is fixed to the gripper arm 142.

Meanwhile, the main guide shaft 250 penetrates the cap 146a and is fastened to the pressure pin 143.

Accordingly, the restoring force of the restoration spring 147 pushes the pressure pin 143, and the pressure pin 143 pushes the link 144 and the gripper pin 145 to protrude the gripper block 149, thereby causing the tool (T) to protrude. This prevents escape.

In addition, when the main guide shaft 250 pulls the pressure pin 143 while compressing the restoration spring 147, the pressure pin 143 pulls the link 144 and the gripper pin 145 to press the gripper block 149. Pull to free the tool (T) from entering and exiting.

The operation of the automatic tool changer 200 of cited invention 1 configured as described above will be explained.

The gripper arm unit 140 stands by at a standby position for tool exchange, and the gripper block 149 stands by in a protruding state in the gripper unit 148.

Afterwards, when a tool exchange command is issued from the NC device, the arm shaft 136 rotates and the gripper arm unit 140 changes its posture to the tool exchange position, and at this time, the cam follower 236 moves the first and second cam surfaces ( It slides along 232)(234).

Since the first cam surface 232 and the second cam surface 234 have a height difference, a change occurs in the gap between the first guide wheel 240 and the second guide wheel 260, and at this time, the first guide wheel Although rotational movement is possible in the fixed housing 210 (240), since it does not advance or retreat, the second guide wheel 260 moves relatively linearly.

In addition, the main guide shaft 250 moves according to the linear movement of the second guide wheel 260, thereby moving the pressure pin 143.

Meanwhile, the pressing pin 143 is pulled while the cam follower 236 is sliding on the first cam surface 232, and the pressing pin 143 is pulled while the cam follower 236 is sliding on the second cam surface 232. (143) is the pushed position.

That is, depending on the phase in which the gripper arm unit 140 is rotated, the cam follower 236 touches the first cam surface 232 or the second cam surface 234, thereby moving the gripper block 149 from the gripper unit 148. By changing the appearance position, the tool (T) is fixed or the tool (T) can be freely entered and exited.

However, in the automatic tool changer 200 of the cited invention 1, in order to prevent the tool T from being separated from the gripper unit 148, the pressure pin 143 of the gripper arm unit 140 is connected to the link 144 and the gripper. The pin 145 must be continuously pressed so that the gripper block 149 grips the tool T with a certain force or more.

However, since the gripper pin 145 is driven only by the link 144, there is a problem of weak rigidity. If the rigidity is weak, an accident may occur where the link 144 is damaged and the held tool (T) comes off.

In addition, as the automatic tool changer 100 is used for a long period of time, the restoring force of the restoration spring 147 attached to the main guide shaft 250 weakens, or the pressure pin 143, link 144, or gripper block 149 ) may cause clearance, which may weaken the tool (T) gripping force.

In this way, when the gripping force of the tool (T) of the gripper arm unit 140 is weakened or a gap occurs, the heavy tool (T) is separated from the gripper block 149 and falls during the tool exchange process, or an unexpected external force is applied to the tool. If applied to (T), an accident may occur in which the tool (T) easily separates from the gripper block 149.

KR 1017967910000 B

The problem of the present invention is to overcome the problems of the prior art as described above. While the tool changer is holding the tool in the gripper unit, the tool is firmly held so that the tool does not escape from the gripper unit due to its weight or external force. Of course, the purpose is to provide an automatic tool changer that complements the rigidity of vulnerable areas and a machine tool including the device.

The automatic tool changing device of the present invention for achieving the above object and the machine tool including the device include an arm shaft that performs rotational and linear movements, and a gripper arm unit installed at a right angle to the end of the arm shaft, Gripper units for gripping or releasing a tool are connected to both ends of the gripper arm unit, and a pair of main guide shafts are installed on both sides of the arm shaft parallel to the axial direction of the arm shaft, with one end of the main guide shaft. In the automatic tool changer unit mechanically connected to the gripper arm unit,

The gripper arm unit,

a joining pin elastically supported from the lower end of the main guide shaft and forming an inclined surface toward the gripper unit;

a gripper pin having an inclined surface formed on one end opposite to the inclined surface of the pressing pin to move forward or backward by sliding with the inclined surface of the pressing pin;

A link rotatably connected to the lower end of the main guide shaft protruding below the pressure pin and one end of the gripper pin having the inclined surface by a link pin to transmit the forward or backward motion of the main guide shaft to the gripper pin. It consists of

In addition, when the main guide shaft is advanced to the maximum for gripping the tool, the link pin position of the link coupled with the main guide shaft is in contact with the pressing pin and the inclined surface of the gripper pin. It is formed to be located horizontally below the position of the coupled link pin.

In addition, the link is characterized in that it is formed in an arc shape, and the link is formed with a long hole so that the link pin connected to the main guide shaft can have a gap within a predetermined length range in the direction of the pipper pin.

The automatic tool changer of the present invention as described above and the machine tool including the device can strengthen the rigidity of vulnerable parts such as links that apply pressure to hold the tool as the automatic tool changer is used for a long period of time. there is.

Additionally, while the tool changer is holding the tool in the gripper unit, it can firmly grip the tool so that it does not come off the gripper unit due to the weight of the tool or even if an external force is applied to the tool.

In addition, even if the tool gripping force weakens or clearance in the operating area occurs when the automatic tool changer is used for a long period of time, the tool can be firmly gripped so that it does not fall out of the gripper unit.

Figure 1 is a perspective view for explaining an automatic tool changing device of the prior art.
Figure 2 is a front view for explaining an automatic tool changing device of the prior art.
Figure 3 is a front view for explaining an automatic tool changing device as an embodiment of the present invention.
Figure 4 is a cross-sectional view of a gripper arm unit in a state in which the gripper pin is retracted to release the grip of the tool, according to an embodiment of the present invention.
Figure 5 is a cross-sectional view of a gripper arm unit with the gripper pin advanced to grip a tool, as an embodiment of the present invention.
Figure 6 is a partial cross-sectional view and perspective view showing the detailed structure of the pressing pin and link in the gripper arm unit as an embodiment of the present invention.
Figure 7 is a top view of a link in a gripper arm unit, as an embodiment of the present invention.

Hereinafter, an automatic tool changing device according to an embodiment of the present invention will be described with reference to FIGS. 3 to 7.

Among the components of the present invention, components referred to by the same names as those in the prior art are given the same symbols as those in the prior art, and detailed description thereof is omitted.

The automatic tool changer 200 according to an embodiment of the present invention is installed with an arm shaft 136 that performs rotational and linear movements, and a gripper arm unit 140 is installed at a right angle to the end of the arm shaft 136. is installed, and the end of the gripper arm unit 140 is connected to a gripper unit 148 that grips or releases the tool T.

Meanwhile, a pair of main guide shafts 250 are installed on both sides of the arm shaft 136 in parallel with the axial direction of the arm shaft 136, and one end of the main guide shaft 250 is the gripper arm unit ( 140) and is mechanically connected.

The gripper arm unit 140 includes a gripper pin 145 whose one end is connected to the gripper block 149 to advance or retract the gripper block 149 in the direction of the gripper unit 148.

The other end of the gripper pin 145 is connected to the lower end of the main guide shaft 250 by a link 144.

Meanwhile, the link 144 is rotatably connected to the gripper pin 145 and the main guide shaft 250 by link pins 273 at both ends, respectively, and the link pin 273 connected to the main guide shaft 250 ) is provided with a long hole 272 formed in the direction of the gripper pin 145.

In addition, a pressure pin 143 is fastened to the lower end of the main guide shaft 250 so that one end of the main guide shaft 250 penetrates.

The pressure pin 143 elastically supports the main guide shaft 250 by installing a restoration spring 147 between the cap 146a that penetrates and is fastened to the main guide shaft 250 at the top thereof.

Additionally, an inclined surface 270 is formed on one side of the pressing pin 143 toward the gripper unit 148.

Meanwhile, one end of the gripper pin 145 facing the inclined surface 270 of the pressing pin 143 has a sliding action against the inclined surface 270 of the pressing pin 143, thereby forming the gripper pin 145. An inclined surface 271 having the same gradient as the inclined surface 270 of the pressing pin 143 is formed so that it can move forward or backward.

Meanwhile, when the main guide shaft 250 advances to the maximum in order to grip the tool T, the link 144 moves toward the inclined surfaces 270 and 271 of the pressing pin 143 and the gripper pin 145. In this sliding contact state, the position of the link pin 273 of the link 144 coupled to the main guide shaft 250 is at a certain angle in the horizontal direction compared to the position of the link pin 273 coupled to the gripper pin 145. It is formed to be located downward by (θ) (see FIG. 5).

Additionally, the link 144 is formed in an arc shape to avoid interference with surrounding components.

Meanwhile, the link 144 is formed with a long hole 272 that can have a gap within a predetermined length range in the direction of the pipper pin 145 at the link pin 273 connected to the main guide shaft 250. do.

Below, we will look at the operating process of the present invention configured as above.

First, the process of gripping the tool T in the gripper unit 148 will be described.

When the main guide shaft 250 descends after the tool (T) is inserted into the gripper unit 148, the main guide shaft 250 rotates the link 144 connected to the bottom in the downward direction, and At the same time, the pressure pin 143 installed at the lower end of the main guide shaft 250 descends together with the inclined surface 270 formed at the lower end.

As the link 144 rotates downward, the other end of the link 144 pushes the gripper pin 145 connected to the link pin 273.

By the pushing action of the gripper pin 145, the gripper block 149 connected to one end of the gripper pin 145 is pushed in the direction of the tool T and the tool T stored in the gripper unit 148 is moved to the gripper unit ( 148).

At the same time, the inclined surface 270 formed on one lower side of the pressing pin 143 slides on the inclined surface 271 formed opposite the end of the gripper pin 145, and pushes the gripper pin 145 in the direction of the gripper unit 148. , Accordingly, the gripper block 149 is pushed in the direction of gripping the tool T stored in the gripper unit 148.

At this time, when the main guide shaft 250 is lowered to its maximum, the inclined surfaces 270 and 271 of the pressure pin 143 and the gripper pin 145 maintain sliding contact and the gripper pin 145 is moved to the gripper unit 148. It is pushed further in the direction, and the position of the link pin 273 of the link 144 coupled to the main guide shaft 250 is rotated further downward to change the position of the link pin 273 coupled to the gripper pin 145. It is located lower by a certain angle (θ) in the horizontal direction (see Figure 5).

As the position of the link pin 273 coupled to the main guide shaft 250 is located horizontally lower than the position of the link pin 273 coupled to the gripper pin 145, the gripper pin 145 is connected to the gripper block. Push (149) to the maximum so that the tool (T) is held in the gripper unit (148) with maximum gripping force.

In this state, its own weight or an external force of a certain force is applied to the tool T held by the gripper unit 149, so that the inclined surface 271 of the gripper pin 145 pushes the inclined surface 270 of the main guide shaft 250. Even if the position of the link pin 273 coupled to the shaft 250 is located horizontally lower than the position of the link pin 273 coupled to the gripper pin 145, the main guide shaft 250 cannot be forcibly pushed up. can not do it. Accordingly, the tool T is maintained in a gripped state within the gripper unit 148.

Next, the process of releasing the grip of the tool T in the gripper unit 148 will be described.

When the main guide shaft 250 can move upward while the tool T is held in the gripper unit 148, the restoration spring 147 installed at the bottom of the main guide shaft 250 The main guide shaft 250 retreats upward.

As the main guide shaft 250 retreats upward, the pressure pin 143 installed at the lower end of the guide shaft 250 also retreats upward, and at the same time, the pressure pin 143 connected to the lower end of the main guide shaft 250 Link 144 also retreats upward.

As the pressing pin 143 and the link 144 retreat upward, the gripper pressing the tool T in the direction of gripping the tool T by the inclined surface 270 of the joining 143 and the link 144 The pin 145 is pulled together with the gripper block 149 in the direction of releasing the grip of the tool T.

As a result, the tool T is exchanged from the tool exchange device 200 to the tool magazine (not shown) or the spindle 20.

Meanwhile, when the main guide shaft 250 is lowered to the maximum or retracted from the maximum lower position to the upper position as described above, the link pin 273 that connects the main guide shaft 250 and the link 144 is Since it has a clearance within a pre-allowed range within the long hole 272 formed in the link 144, the link pin 273 of the main guide shaft 250 exerts the descending force of the main guide shaft 250 and the restoration spring ( Due to the restoring force of 147), the link pin 273 coupled with the gripper pin 145 can move downward or retreat by a certain angle θ in the horizontal direction.

In addition, since the link 144 has an arc shape, it is possible to avoid interference with surrounding structures when the link 144 rotates according to the forward and backward motion of the main guide shaft 250.

In this way, the automatic tool changer of the present invention and the machine tool including the automatic tool changer use the automatic tool changer 200 for a long period of time, and the link 144 that acts as a pressure to hold the tool T is used. The rigidity of vulnerable areas such as can be strengthened.

While the tool (T) is being held in the gripper unit 148, the tool (T) is firmly secured so that it does not escape from the gripper unit (148) due to the weight of the tool (T) or even if an external force is applied to the tool (T). It can be grasped.

In addition, even if the tool gripping force weakens or clearance in the operating area occurs due to use of the automatic tool changer 200 for a long period of time, the tool (T) is firmly held so as not to be separated from the gripper unit 148, and the tool (T) is held in the vulnerable area. It has the effect of providing an automatic tool changer with improved rigidity.

20: spindle
T: Tool
102: Cam box
130: main shaft
132: Groove
134: polygonal shaft
136: Arm shaft
140: Gripper arm unit
142: Gripper arm
143: Pressure pin
144: Link
145: Gripper pin
146a: cap
147: restoration spring
148: Gripper unit
149: Gripper block
200: Automatic tool changer
210: fixed housing
230: Cam unit
232: first cam surface
234: second cam surface
236: Cam Follow
240, 260: first and second guide wheels
250: main guide shaft
254: Sub guide shaft
270,271: slope
272: Janggong
273: Link pin

Claims (5)

An arm shaft 136 that performs rotary and linear motion, and a gripper arm unit 140 are installed at a right angle to the end of the arm shaft 136, and a tool (T) is installed at both ends of the gripper arm unit 140. ) is connected to a gripper unit 148 that grips or releases the arm shaft 136, and a pair of main guide shafts 250 are installed on both sides of the arm shaft 136 parallel to the axial direction of the arm shaft 136. In the automatic tool changer, one end of the main guide shaft 250 is mechanically connected to the gripper arm unit 140,
The gripper arm unit 140,
a pressure pin 143 elastically supported from the lower end of the main guide shaft 250 and forming an inclined surface 270 toward the gripper unit 148;
A gripper pin 145 having an inclined surface 271 formed on one end opposite to the inclined surface 270 of the pressing pin 143 to move forward or backward by sliding with the inclined surface 270 of the pressing pin 143, and ,
The lower end of the main guide shaft 250 protruding below the pressing pin 143 and one end of the gripper pin 145 having the inclined surface 271 are rotatably connected to the link pin 273. It consists of a link 144 that transmits the forward or backward motion of the main guide shaft 250 to the gripper pin 145,
The link 144 is such that the inclined surface 270 of the pressing pin 143 and the inclined surface 271 of the gripper pin 145 contact when the main guide shaft 250 is advanced to the maximum to grip the tool. In this state, the position of the link pin 273 coupled to the main guide shaft 250 is positioned horizontally lower than the position of the link pin 273 coupled to the gripper pin 145, An automatic machine tool, characterized in that a long hole 272 having a gap within a predetermined length range in the direction of the gripper pin 145 is formed at the position of the link pin 273 connected to the main guide shaft 250. Tool changer. delete The automatic tool changer for a machine tool according to claim 1, wherein the link (144) has an arc shape. delete A machine tool including the automatic tool changer according to any one of claims 1 or 3.