JP3206020U - Work gripping device and machine tool provided with the same - Google Patents

Abstract

A work gripping device capable of driving a hand to a gripping state or an open state while being attached to a spindle of a machine tool without requiring a special drive source. A main body 10 connected to a spindle of a machining center, a cylinder 12 into which a coolant liquid is press-fitted, a piston 13 slidably disposed in the cylinder, and a piston is constantly pressed in a direction opposite to an extrusion direction. A spring member 18, two hand members 26 and 27 having pads 28 and 29 at their tips, and a drive mechanism for the hand member, and the drive mechanism is a hand member 26 that is rotatably connected to the piston as a link. 27, and plate members 21 and 22 pivotably connected to the hand member and the main body, and the gripping state in which the pads 28 and 29 of the hand member are brought close to each other by the movement of the piston, Drive to open state. [Selection] Figure 1

Description

  The present invention relates to a clamping device used by attaching to a spindle of a machine tool, such as a machining center, and a machine tool having the same.

  Conventionally, various processes are performed by holding a workpiece in a machine tool, for example, a machining center, and exchanging and attaching a tool to a spindle. In such a machining center, a workpiece gripping device is used for exchanging the workpiece and changing the direction and posture of the workpiece.

  Such a workpiece gripping device is driven by electricity or hydraulic pressure. For this reason, a drive source and drive control circuit different from the drive source and drive control circuit of the machining center are required for the workpiece gripping device. In response to this, there has been proposed an apparatus in which the clamping device is driven by the coolant pressure supplied to the spindle of the machining center.

In Patent Document 1, a clamping device that clamps a workpiece by a machining center or the like is driven by a coolant supplied from a main shaft, and the clamping device includes a cylinder, a piston, a piston rod, an accumulator, and the like. The pressure is held in the accumulator, and the piston is driven by the pressure accumulated in the accumulator when the main shaft is detached from the clamping device.
JP-A-2005-59104

  However, the one disclosed in Patent Document 1 connects a coolant injection portion attached to a main shaft to a clamp-side coupler, pumps the coolant liquid, accumulates the pressure of the coolant liquid in an accumulator, and drives the cylinder device of the clamp device. It is said. For this reason, the apparatus is large and expensive. Also, the clamp device must be controlled separately from the machining center.

  The present invention has been made in view of the above-described problems, and provides a workpiece gripping device that can drive a hand in a gripping state or an open state while being attached to a spindle of a machine tool without requiring a special drive source. Objective.

The device according to claim 1, which solves the problem, is a main body connected to a main shaft of a machine tool and connected to a coolant liquid supply passage formed on the main shaft, and the coolant disposed inside the main body. A cylinder part into which coolant liquid from a liquid supply path is press-fitted, a piston slidably disposed in the cylinder part and pushed out by the pressure of the coolant liquid, and constantly pressing the piston in a direction opposite to the pushing direction, A spring member that pushes the piston into the cylinder when the pressure of the coolant liquid in the cylinder is released; a plurality of hand members each having a grip portion at a tip; and a drive mechanism for the hand member; The mechanism is rotatably connected to the piston as a link, and to the hand member and the main body. A workpiece gripping device configured as a link mechanism including a rate member and driving in a gripping state in which the gripping portion of the hand member is brought close by movement of the piston and an open state in which the gripping portion is separated. is there.
According to the present invention, the workpiece gripping device connected to the spindle of the machine tool is such that when the coolant liquid is pressed into the cylinder, the piston is pushed out against the spring member, while when the coolant liquid pressure is released, the piston is The member is pushed back into the cylinder, and the driving mechanism is operated by the operation of the cylinder, so that the hand member is in a gripping state or an open state.
In addition, since the drive mechanism of the hand member is composed of a link mechanism using the hand member and the plate member as a link, it can be reliably operated with a simple structure and can be manufactured at low cost.
As a result, the hand member can be driven to a simple and inexpensive gripping state or open state in a state where the hand member is attached to the spindle of the machine tool without requiring a special driving source.

Similarly, the invention described in claim 2 is characterized in that it is arranged in a tool cassette of the machine tool and is exchangeably attached to the main shaft.
According to the present invention, the workpiece gripping device is disposed in a tool cassette of a machine tool together with other cutting tools or the like normally used for machining a workpiece, and is attached to the spindle so as to be replaceable.
For this reason, it is possible to attach the workpiece gripping device to the spindle during machining of a series of workpieces in the machine tool.

Similarly, the invention according to claim 3, the hand member is in an open state when the coolant liquid is press-fitted into the cylinder part and the piston is pushed out of the cylinder part, and the pressure of the coolant liquid is reduced. Then, when the piston is pushed in by the spring member, it is in a gripping state.
According to the present invention, the plurality of gripping members in the hand member are opened when the coolant liquid is press-fitted, and are pushed back by the spring member when the pressure of the coolant liquid is lowered.
Therefore, it is only necessary to control whether the coolant is pumped or returned when the hand member is driven to the open state and the gripping state. Further, since the hand member is held by the force of the spring member, the workpiece can be held with a constant force regardless of the pressure of the coolant liquid.

Similarly, the invention described in claim 4 is a machine tool characterized in that the work gripping device is arranged in a tool cassette together with a tool for attaching the work gripping device to a main shaft.
According to the present invention, in a machine tool, a workpiece gripping device is disposed in a tool cassette together with other cutting tools or the like normally used for machining a workpiece, and is attached to a main shaft in a replaceable manner.
For this reason, it is possible to attach the workpiece gripping device to the spindle during machining of a series of workpieces in the machine tool.

Similarly, the invention of claim 5 is a tool mounting means for mounting one of the tools including the workpiece gripping device held in the tool cassette to the main shaft, and a coolant liquid pressure feeding device for pumping the coolant liquid to the main shaft. And spindle driving means for performing a preset operation on the spindle with the workpiece gripping device attached thereto.
According to the present invention, the workpiece gripping device held in the tool cassette by the tool mounting means is attached to the spindle, and the coolant is pumped by the coolant liquid feeding means while the spindle driving means performs a predetermined operation on the spindle. The gripping device can be driven.
Thereby, the workpiece can be gripped and moved by the workpiece gripping device, or the posture of the workpiece can be changed.

  According to the workpiece gripping device and the machine tool according to the present invention, the hand can be opened and closed while being attached to the spindle of the machine tool without requiring a separate drive source.

  That is, according to the workpiece gripping device of the first aspect, the workpiece gripping device connected to the spindle of the machine tool pushes the piston against the spring member when the pressure of the coolant liquid acts on the cylinder, and the hand member When the coolant pressure is released, the piston is pushed back into the cylinder by the spring member and the hand member is gripped, and it is attached to the spindle of the machine tool without requiring a special drive source. The hand can be driven to a gripping state or an open state. In addition, since the drive mechanism of the hand member is composed of a link mechanism including a hand member, a sliding node, and a plate member arranged so as to be able to rotate, it can operate reliably with a simple structure and is inexpensive. Can be manufactured.

  According to the workpiece gripping device of claim 2, the workpiece gripping device is disposed in the tool cassette of the machine tool together with other cutting tools or the like normally used for machining the workpiece, and is attached to the main shaft in a replaceable manner. The workpiece gripping device can be attached to the spindle during the machining of a series of workpieces.

  According to the workpiece gripping device of the third aspect, the plurality of gripping members in the hand member are opened when the coolant liquid is press-fitted, and are pushed back by the spring member when the coolant liquid pressure is lowered. Therefore, it is only necessary to control whether the coolant liquid is pumped or returned when the hand member is driven to the open state and the gripping state. Further, since the hand member is held by the force of the spring member, the workpiece can be held with a constant force regardless of the pressure of the coolant liquid.

  According to the machine tool of the fourth aspect, in the machine tool, the workpiece gripping device is disposed in the tool cassette together with other cutting tools or the like normally used for machining the workpiece, and is attached to the spindle so as to be replaceable. The workpiece gripping device can be attached to the spindle during machining of a series of workpieces in the machine.

  According to the machine tool of claim 5, the workpiece gripping device held in the tool cassette by the tool attachment means is attached to the spindle, and the coolant is fed by the coolant hydraulic pressure feeding means while the spindle drive means performs a predetermined operation on the spindle. Since the workpiece gripping device can be driven by pumping the liquid, the workpiece can be gripped and moved by the workpiece gripping device or the posture of the workpiece can be changed.

1 shows a workpiece gripping device according to an embodiment of the present invention, wherein (a) is a cross-sectional view of the workpiece gripping device in an open state, (b) is a side view of the workpiece gripping device in an open state, and (c) is a gripping state. It is sectional drawing of the workpiece | work holding | gripping apparatus in FIG. It is a perspective view showing the work gripping device. 1 is an external view of a machining center that is a machine tool according to an embodiment of the present invention. It is a schematic diagram which shows the pumping control system of the coolant liquid in the workpiece holding device. It is a schematic diagram which shows the 1st example of operation | movement of the workpiece | work holding | grip apparatus in the machining center. It is a schematic diagram which shows the 2nd example of operation | movement of the workpiece holding apparatus in the machining center. It is a schematic diagram which shows the 3rd example of operation | movement of the workpiece holding apparatus in the machining center.

  A workpiece gripping device and a machine tool according to an embodiment for carrying out the present invention will be described.

  First, a workpiece gripping device according to an embodiment will be described. 1A and 1B show a workpiece gripping device according to an embodiment of the present invention, wherein FIG. 1A is a sectional view of the workpiece gripping device in an open state, FIG. 1B is a side view of the workpiece gripping device in an open state, and FIG. FIG. 2 is a perspective view showing the workpiece gripping device. FIG. 3 is a schematic view showing a drive system of the workpiece gripping apparatus, and FIG. 4 is an external view of a machining center which is a machine tool according to an embodiment of the present invention.

  In the embodiment of the present invention, the workpiece gripping device 30 includes a main body portion 10 and a hand portion 20 as shown in FIGS. 1 and 2. As shown in FIG. 4, the workpiece gripping device 30 is used by being attached to a spindle 51 of a machining center 50.

  First, the main body 10 will be described. The main body 10 includes an arbor 11, a cylinder 12, a piston 13, and a rod 15. The arbor 11 is inserted into the main shaft 51 of the machining center 50 and has a tapered shape. Inside the arbor 11, a coolant liquid passage 11a is provided. In the arbor 11, a cylinder 12 is formed in communication with the passage 11a. The piston 13 is disposed in the cylinder 12, and an O-ring 14 is disposed between the piston 13 and the cylinder 12. When the coolant is pumped to the cylinder 12 through the passage 11a, the piston 13 is pushed out to the side opposite to the passage 11a. FIG. 1A shows a state where the piston 13 is pushed out. In addition, the arbor 11 is provided with an engaging portion 11b with which the automatic tool changer 56 is engaged.

  Further, a rod housing 16 is disposed on the arbor 11. The rod housing 16 encloses the cylinder 12 and includes a spring member 18. The spring member 18 is a coil spring. The spring member 18 is disposed around the rod 15 in a compressed state, and presses the piston 13 toward the passage 11a. The spring member 18 is pushed in a state where the coolant liquid is pumped to the cylinder 12 (FIG. 1A). On the other hand, when the pressurization to the coolant liquid pumped from the passage 11a is stopped and the pressure is released, the spring member 18 pushes the piston 13 back toward the passage 11a in the cylinder 12 (FIG. 1B).

  With such a configuration, the main body portion 10 moves the rod 15 in and out of the rod housing 16 by pumping the coolant liquid or releasing the pumping.

  Next, the hand unit 20 will be described. The hand unit 20 includes a plurality of hand members 26 and 27 in this example. In the workpiece gripping device 30, the hand members 26 and 27 are driven by the rod 15 that moves in and out, so that the workpiece can be gripped (see FIG. 1B), or the workpiece is released (FIG. 1B). ) To drive.

  The hand unit 20 includes plate members 21 and 22, link pins 23 and 24, and a head pin 25. The plate members 21 and 22 are plate-shaped metal members. The plate members 21, 22 are rotatably connected to the rod housing 16 at one ends 21 a, 22 a on the main body 10 side by link pins 23, 23. Further, the other ends 21 b and 22 b of the plate members 21 and 22 are rotatably connected to the hand members 26 and 27 by link pins 24 and 24. The link pins 23 and 24 are prevented from coming off by C-shaped rings 23a and 24a.

  In the present embodiment, as shown in FIG. 1C, two plate members 21 and 22 are arranged with the rod 15 in between, so that the hand members 26 and 27 are provided with a driving force without bias. .

  The hand members 26 and 27 are bent metal plate-like members, and pads 28 and 29 which are gripping portions are disposed at the respective distal ends 26a and 27a. The pads 28 and 29 are made of a material that does not damage the work and is difficult to slip when it comes into contact with the work, for example, hard rubber. The pads 28 and 29 are fixed to the hand members 26 and 27 with, for example, bolts. The hand members 26 and 27 are attached to the distal end portion 17 of the rod 15 together with the base ends 26b and 27b by a single head pin 25. The head pin 25 is prevented from coming off by a C-shaped ring 25a. Furthermore, the other ends 21b and 22b of the plate members 21 and 22 described above are disposed on both sides of the hand members 26 and 27 with the location where the head pin 25 is attached.

  With the above configuration, the hand unit 20 forms a link mechanism in which the hand members 26 and 27, the plate members 21 and 22 are links, the link pins 23 and 24, and the head pins 25 are joints. In other words, the hand unit 20 is driven by the head pin 25 that moves linearly by the protrusion and withdrawal of the rod 15 and constitutes a link mechanism in which the hand members 26 and 27 are opened and closed via the plate members 21 and 22.

  For this reason, the hand unit 20 according to the present embodiment has a simple configuration as compared with the case where a rack and pinion or a gear mechanism is used. Therefore, the workpiece gripping device 30 according to the present embodiment has advantages such as easy miniaturization, reliable operation, and easy manufacture at low cost.

  In addition, according to the workpiece gripping device 30 according to the present embodiment, since the hand members 26 and 27 are driven by the spring member 18 when gripping the workpiece, a constant force is always obtained regardless of fluctuations in the pumping force of the coolant liquid. And can grip the workpiece at speed.

  Next, a machining center will be described as a machine tool including the workpiece gripping device according to the embodiment. FIG. 3 is an external view of a machining center that is a machine tool according to an embodiment of the present invention, and FIG. 4 is a schematic diagram showing a drive system of the workpiece gripping device.

  A machining center 50 according to an embodiment of the present invention includes a main shaft 51, a saddle 52, a column 53, an index table 54, a tool magazine 55, and an automatic tool changer 56.

  The spindle 51 is attached with a tool including the workpiece gripping device 30 and can be driven to rotate in the forward and reverse directions (arrow r in the figure). The main shaft 51 is disposed on a saddle 52, and the saddle 52 can be driven in the width direction (arrow X direction in the figure) and the vertical direction (arrow Y direction) with respect to the column 53. Note that the column 53 is disposed on the base 59. Further, the main shaft 51 can be driven in the axial direction (the arrow Z direction in the figure). The main shaft 51 is formed with a coolant liquid supply path through which the coolant liquid is pumped. Further, the index table 54 can be driven to rotate with the work fixed.

  Various tools 57 including the workpiece gripping device 30 are installed in the tool magazine 55, and the automatic tool changer 56 selects and designates the designated tool from the tool magazine 55 and installs it on the spindle 51. As a result, in the machining center 50, the selected tool 57 is set on the spindle 51 from the tool magazine 55 by the automatic tool changer 56. The tool including the workpiece gripping device 30 has five degrees of freedom with respect to the index table 54, and performs various processing and processing on the workpiece.

  In the machining center 50, tool exchange, rotation control and movement control of the spindle 51, movement control of the saddle 52, drive control of rotation control of the index table 54, and pumping control of coolant liquid are performed according to a program by a control device constituted by a computer. Is called. This program is prepared in advance to specify the machining content of the workpiece.

  Next, a control system for pumping the coolant to the workpiece gripping device 30 will be described. FIG. 4 is a schematic diagram showing a coolant liquid pressure feed control system in the workpiece gripping apparatus. In the present embodiment, the coolant pressure feed control system 40 includes a coolant liquid tank 41, a filter 42, a coolant pump 43, a three-way valve 44, and a pressure switch 45.

  The coolant liquid is stored in the coolant liquid tank 41. The filter 42 removes foreign matter from the coolant liquid being pumped. The coolant pump 43 pumps the coolant liquid. The three-way valve 44 controls whether to supply the coolant from the coolant pump 43 to the workpiece gripping device 30 or to return the coolant fluid from the workpiece gripping device 30 to the coolant fluid tank 41 by controlling the pressure switch 45. The pressure switch 45 is driven under the control of the control device of the machining center 50 described above.

When the three-way valve 44 is pumped by the pressure switch 45 (the state shown in FIG. 4), the coolant liquid from the coolant pump 43 is pumped to the cylinder 12 from the passage 11a formed in the arbor 11 of the workpiece gripping device 30, The piston 13 moves and the hand unit 20 is opened.
On the other hand, when the three-way valve 44 is returned by the pressure switch 45, the pressure in the cylinder 12 decreases in the workpiece gripping device 30, the piston 13 is pushed back by the spring member 18, and the hand portion 20 is gripped.

  In the machining center 50, the control device controls the replacement of the tool attached to the main shaft 51, rotation (r direction) and movement of the main shaft (Z direction), movement of the saddle 52 (X and Y directions), rotation of the index table 54 (R direction). To control the workpiece. In the present embodiment, the opening and gripping operations of the hand unit 20 are controlled by being incorporated in the processing flow, the workpiece is gripped during the processing of the workpiece, and the movement and posture change of the workpiece are realized. Therefore, the control of the gripping state and the open state of the workpiece gripping device 30 is incorporated in the workpiece machining program.

  Hereinafter, an example of processing using the workpiece gripping device 30 in the machining center 50 will be described. FIG. 5 is a schematic diagram showing a first example of the operation of the workpiece gripping apparatus in the machining center. In this example, the workpiece gripping device 30 performs processing by placing the unprocessed workpiece Wb placed on the unprocessed pallet 61 on the index table 54, and then processing the processed workpiece Wa from the index table 54 to the processed pallet 62. It is to be moved.

  In this example, first, the machining center 50 installs the workpiece gripping device 30 on the spindle 51 under the control of the drive control unit. Then, the machining center 50 moves the spindle 51 and moves the workpiece gripping device 30 to the position of the unprocessed workpiece Wb arranged on the unprocessed pallet 61 to drive the hand unit 20 to grip the workpiece Wb. Further, the machining center 50 moves the spindle 51 and moves the workpiece Wb to the index table 54. Next, the machining center 50 removes the workpiece gripping device 30 from the main shaft 51, attaches a predetermined tool 57 such as a cutting tool, etc., operates each part, and performs processing specified in advance on the workpiece W.

  Further, the machining center 50 removes the cutting tool from the spindle 51 and attaches the workpiece gripping device 30, moves the spindle 51 and moves the workpiece gripping device 30 to the position of the processed workpiece Wa arranged on the index table 54. The hand unit 20 is driven to grip the workpiece Wb. Then, the machining center 50 moves the spindle 51 and moves the processed workpiece Wa to the processed pallet 62.

  The above operation is designated by a program in advance in the control device of the machining center 50. At this time, replacement of the workpiece gripping device 30 and pressure control of the coolant liquid can also be specified as a series of workpiece machining procedures. For this reason, it is not necessary to control the workpiece gripping device 30 separately from the machining program.

  FIG. 6 is a schematic diagram showing a second example of the operation of the workpiece gripping device in the machining center. In this example, the posture of the workpiece W being processed is changed by the workpiece gripping device 30. That is, as shown in FIG. 6 (a), the workpiece W is processed with the tool 57 attached to the spindle 51. After the machining, the workpiece gripping device 30 is attached to the spindle 51, and the workpiece W is gripped. For example, 51 is rotated by 90 degrees. Then, the work is returned to the index table 54.

  Thereby, the posture of the workpiece W can be changed during a series of machining operations of the machining center 50.

  FIG. 7 is a schematic diagram showing a third example of the operation of the workpiece gripping apparatus in the machining center. In this example, the workpiece W is moved to the cleaning position where the cleaning nozzle 63 is arranged by the workpiece gripping device 30 and the workpiece W is cleaned while changing the posture of the workpiece W. That is, as shown in FIG. 7, chips 64 generated by processing are attached to the workpiece W. The machining center 50 grips the workpiece W with the workpiece gripping device 30 attached to the spindle 51, moves to the cleaning position, and cleans it with the cleaning liquid 65 ejected from the cleaning nozzle 63. At this time, the position and posture of the workpiece W are changed so that the cleaning liquid 65 can be sprayed to the concave portion or the like of the workpiece W by moving or rotating the workpiece gripping device 30. Thereby, the chip | tip 64 adhering to the workpiece | work W can be removed efficiently.

  The workpiece gripping device and machine tool according to the present invention do not require a special drive source, and the workpiece can be driven in a gripping state or an open state with the device mounted on the spindle of the machine tool. It can be used and has industrial applicability.

10: drive unit 11: arbor 11a: passage 11b: engagement unit 12: cylinder 13: piston 14: O-ring 15: rod 16: rod housing 17: tip 18: spring member 20: hand unit 21, 22: plate member 21a, 22a: one end (plate member)
21b, 22b: the other end (plate member)
23, 24: Link pin 23a, 24a: C-type ring 25: Head pin 25a: C-type ring 26, 27: Hand member 26a, 27a: Tip (hand member)
26b, 27b: proximal end (hand member)
28, 29: Pad 30: Work gripping device 40: Coolant fluid pressure control system 41: Coolant fluid tank 42: Filter 43: Coolant pump 44: Three-way valve 45: Pressure switch 50: Machining center 51: Spindle 52: Saddle 53: Column 54 : Index table 55: Tool magazine 56: Automatic tool changer 57: Tool 59: Base 61: Unprocessed pallet 62: Processed pallet 63: Cleaning nozzle 64: Chip 65: Cleaning liquid W: Workpiece

Claims (5)

A main body connected to a spindle of a machine tool and connected to a coolant liquid supply passage formed on the spindle;
A cylinder part that is arranged inside the main body part and into which coolant liquid from the coolant liquid supply path is press-fitted, and
A piston that is slidably disposed in the cylinder portion and is pushed out by the pressure of the coolant liquid;
A spring member that constantly pushes the piston in a direction opposite to the pushing direction and pushes the piston into the cylinder when the pressure of the coolant in the cylinder is released;
A plurality of hand members having a gripping portion at the tip;
A drive mechanism for the hand member;
With
The drive mechanism is configured as a link mechanism including the hand member rotatably connected to the piston as a link, and a plate member rotatably connected to the hand member and the main body, and the piston The workpiece gripping device is driven to move to a gripping state in which the gripping portion of the hand member is brought close to and in an open state in which the gripping portion is separated.   The work gripping device according to claim 1, wherein the work gripping device is disposed in a tool cassette of the machine tool and is replaceably attached to the spindle.   The hand member is opened when the coolant liquid is pressed into the cylinder part and the piston is pushed out of the cylinder part, and the piston is pushed in by the spring member in a state where the pressure of the coolant liquid is reduced. The workpiece gripping device according to claim 1 or 2, wherein the workpiece gripping device is brought into a gripping state.   A machine tool, wherein the workpiece gripping device according to any one of claims 1 to 3 is disposed in a tool cassette together with a tool to be attached to the spindle.   A tool mounting means for mounting one of the tools including the work gripping device held in the tool cassette to the main shaft, a coolant liquid pressure feeding device for pumping the coolant liquid to the main shaft, and a state in which the work gripping device is mounted. The machine tool according to claim 4, further comprising: a spindle driving means for causing the spindle to perform a preset operation.