Machine tool

Abstract

To provide a machine tool capable of changing a tool with a simple structure.SOLUTION: A machine tool 10 includes a frame 11, and a ram 21 which is arranged on the frame 11 so as to reciprocate and has a trigger hole 21a. A feed unit 38 includes a spindle 23 having a ring pin hole 23c, a draw bar 24 having a collet 28, capable of reciprocating in the spindle 23, and energized in a base end direction of the spindle 23, an unclamp ring 31 arranged outside in a radial direction of the spindle 23, and connected to the draw bar 24 through the ring pin hole 23c, a trigger 35 fixed to a frame 11, and penetrating a trigger hole 21a, and reciprocates a ram 21. And a feed unit 38 for advancing the draw bar 24 relative to the main spindle 23 to open the collet 28 by advancing the ram 21 in the tip direction to machine the workpiece and retracting the ram 21 in the base end direction to bring the unclamp ring 31 into contact with the trigger 35.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a machine tool. [Background technology]

[0002] For example, a drilling machine disclosed in Japanese Patent Application Laid-Open No. 2022-071706 is known. This drilling machine has a frame, a linear guide, a slider, a ram, a spindle, a spindle motor, a feed screw, and a feed motor. The frame has a linear guide support plate with a reference surface, a ram support plate with a ram guide hole, and a motor support portion. The linear guide is disposed on the reference surface. The slider reciprocates along the linear guide. The ram is disposed on the slider and passes through the ram guide hole. The main shaft is journaled within the ram. The main shaft motor is connected to the main shaft. The feed screw has a nut disposed on the slider and a screw shaft with one end journaled on the motor support portion and the other end free. The feed motor is connected to the screw shaft. Summary of the Invention [Problem to be solved by the invention]

[0003] An object of the present invention is to provide a machine tool that has a simple structure and allows tool replacement. [Means for solving the problem]

[0004] A first aspect of the present invention is The frame and a hollow ram reciprocably disposed on the frame, the ram having a trigger hole extending radially through the ram and axially therethrough; a hollow spindle to which a tool can be attached and which is rotatably supported by the ram, the spindle having a ring pin hole which passes radially through the spindle and extends axially; a drawbar having a collet and reciprocating within the spindle, the drawbar being biased toward the base end of the spindle; an unclamping ring disposed radially outward of the spindle and connected to the draw bar through the ring pin hole; a trigger fixed to the frame and passing through the trigger hole; A feed unit for reciprocating the ram, The ram is advanced in a tip direction to machine the workpiece; the ram is retracted in a proximal direction to bring the unclamping ring into contact with the trigger, thereby advancing the draw bar relative to the spindle and opening the collet. A feeding unit; It is a machine tool having the above.

[0005] The machine tool is mounted on a robot arm or slide table, and rotates the spindle and feeds the ram (21) to perform milling, drilling, and tapping operations. The trigger may be a trigger block extending in a plane perpendicular to the spindle, the trigger block being disposed between the spindle and the ram. Preferably, the spindle is supported by the ram at three points: the tip, center, and base end of the spindle. The support position of the center of the spindle may be closer to the tip than the unclamping ring. The spindle is supported by the ram by main bearings. The guide block may be integral with the main shaft.

[0006] The machine tool may include an elastic body that biases the draw bar in the proximal direction relative to the spindle. The elastic body may be disposed between the draw shaft and the elastic body chamber. The elastic body may be disposed between the draw block and the elastic body chamber. The main shaft drive shaft is disposed coaxially with the main shaft and extends along the central axis of the main shaft. The unclamping ring has an abutment surface that abuts against the trigger. The abutment surface is located at a proximal end of the unclamping ring. [Effects of the Invention]

[0007] According to the present invention, a machine tool capable of tool replacement with a simple structure can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a longitudinal sectional view of a machine tool according to a first embodiment; [Figure 2] Arrow II view of Figure 1 [Figure 3] Cross section of line III-III in Figure 1 [Figure 4] FIG. 10 is a longitudinal sectional view of a machine tool according to a second embodiment. [Figure 5] Cross section of line VV in Figure 4 [Figure 6] Cross section of Figure 4 along line VI-VI DETAILED DESCRIPTION OF THE INVENTION

[0009] <Embodiment 1> As shown in Figures 1 to 3, machine tool 10 of this embodiment has a frame 11, a linear guide 17, a connection block 19, a housing 13, a bearing 14, a drive shaft (main shaft drive shaft) 15, a ram 21, a main bearing 22, a main shaft 23, a drawbar 24, a guide block 26, an unclamping ring 31, a ring pin 33, a feed unit 38, a main shaft motor 41, a driving pulley (second driving pulley) 47, a driven pulley (second driven pulley) 45, and an endless belt (second endless belt) 48.

[0010] The feed unit 38 includes a feed screw 39, a bearing 32, a feed motor 43, a driving pulley (first driving pulley) 51, a driven pulley (first driven pulley) 49, and an endless belt (first endless belt) 52.

[0011] 1 is a cross-sectional view taken along line II in FIG. 2. Line II connects the central axis 3 of the main shaft 23, the central axis of the feed screw 39, and the center of the output shaft of the feed motor 43. The top of Figure 1 is the proximal direction (+Z). The bottom of Figure 1 is the distal direction (-Z). For convenience, the right direction of Figure 1 is referred to as the downward direction (+Y). For convenience, the left direction of Figure 1 is referred to as the upward direction (-Y). For convenience, the direction penetrating the page of Figure 1 is referred to as the left-right direction (X).

[0012] The frame 11 is box-shaped. The frame 11 has a base plate 11a, a ram support plate 11b, a drive shaft support plate 11c, and a side plate 11d (see FIG. 3). The ram support plate 11b has a ram hole 11f. The drive shaft support plate 11c has a housing hole 11g (see FIG. 3) and a screw support hole 11h. The ram hole 11f and the housing hole 11g extend along the central axis 3.

[0013] The linear motion guide 17 has a linear motion rail 17a and a linear motion block 17b. The linear motion rail 17a extends parallel to the central axis 3 and is disposed on the base plate 11a. The linear motion block 17b reciprocates on the linear motion rail 17a.

[0014] The connection block 19 connects the ram 21, the feed screw 39, and the linear motion block 17b. The connection block 19 moves back and forth on the linear motion guide 17 together with the ram 21. The connection block 19 is a rectangular plate. The lower end of the connection block 19 is fastened to the linear motion block 17b. The connection block 19 has a drive shaft hole 19a and a nut hole 19b. The drive shaft hole 19a is located at the bottom of the connection block 19. The nut hole 19b is located at the top of the connection block 19. The drive shaft hole 19a extends along the central axis 3 and passes through the connection block 19.

[0015] As shown in FIG. 1, the housing 13 is hollow and cylindrical, and is disposed in the housing hole 11g. Preferably, the housing 13 can be inserted into the housing hole 11g from the base end direction (+Z direction). The housing 13 supports the drive shaft 15 via a bearing 14. The housing 13 may be integral with the drive shaft support plate 11c. The housing 13, bearing 14, and drive shaft 15 can be removed from the frame 11 as a unit.

[0016] As shown in FIG. 3, the drive shaft 15 has a spline shaft 15a, a support shaft 15b, a coolant passage (first coolant passage) 15c, and a supply port (coolant supply port) 15d. The drive shaft 15 extends along the central axis 3 and passes through a drive shaft hole 19a. The base end of the drive shaft 15 is supported by the housing 13. The base end of the drive shaft 15 protrudes toward the base end beyond the housing 13 and the drive shaft support plate 11c. The spline shaft 15a is disposed at the center of the drive shaft 15 in the axial direction. The support shaft 15b is disposed at the tip of the drive shaft 15. The support shaft 15b is a right circular cylinder. The coolant passage 15c extends along the central axis 3 and passes through the drive shaft 15. The supply port 15d is disposed at the base end of the drive shaft 15 and is connected to the coolant passage 15c. The supply port 15d is, for example, a female pipe thread.

[0017] The ram 21 is hollow cylindrical and extends along the central axis 3. The base end of the ram 21 is fastened to the connection block 19. The tip end of the ram 21 passes through the ram hole 11f. The ram 21 slides axially relative to the ram hole 11f. The ram 21 reciprocates integrally with the connection block 19. As shown in FIG. 3, the ram 21 has a trigger hole 21a. The trigger hole 21a is disposed on a left-right plane (ZX plane). The left-right plane (ZX plane) is a plane that passes through the central axis 3 and extends in the left-right direction. The trigger hole 21a passes radially through the ram 21. The trigger hole 21a is an elongated hole that extends axially.

[0018] The main shaft 23 is hollow cylindrical and extends along the central axis 3. The main shaft 23 is supported by the ram 21 via a main bearing 22. As shown in FIG. 3, the main shaft 23 has, in order from the base end, a spline hole 23a, a drive shaft chamber 23b, a spring chamber (elastic body chamber) 23d, a through hole 23e, a collet chamber 23f, and a main shaft hole 23g. The spline hole 23a meshes with the spline shaft 15a. The drive shaft chamber 23b is connected to the spline hole 23a and the spring chamber 23d. The main shaft hole 23g is connected to the collet chamber 23f. The through hole 23e connects the collet chamber 23f and the spring chamber 23d. The tool 1 is attached to the spindle hole 23g and has a stud bolt 1b.

[0019] The guide block 26 is a hollow right circular cylinder. The guide block 26 has an outer surface 26a and a guide hole 26b. The outer surface 26a abuts against the inner surface of the drive shaft chamber 23b and slides in the axial direction. The guide hole 26b abuts against the outer surface of the support shaft 15b. The guide hole 26b slides in the axial direction with the support shaft 15b. The support shaft 15b is supported by the main shaft 23 via the guide block 26. The guide hole 26b is part of the second coolant flow path.

[0020] The draw bar 24 is disposed at the tip of the main shaft 23. The draw bar 24 reciprocates inside the main shaft 23. The draw bar 24 has a draw block 25, a draw shaft 27, and a collet 28. 3, draw block 25 has a hollow cylindrical shape and includes a body 25a, a shaft support hole 25d, a coolant passage (second coolant passage) 25c, and a pin fixing hole 25e.

[0021] Body 25a is connected to guide block 26. Shaft support hole 25d and coolant passage 25c extend along central axis 3. Shaft support hole 25d is disposed at the tip of body 25a and opens to the tip of body 25a. Coolant passage 25c connects guide hole 26b and shaft support hole 25d. Pin fixing hole 25e extends radially and penetrates body 25a. Pin fixing hole 25e is a cylindrical hole.

[0022] The draw shaft 27 has a hollow cylindrical shape. The draw shaft 27 passes through the through hole 23e and is fastened to the shaft support hole 25d. The draw shaft 27 has a coolant flow path (second coolant flow path) 27b. The collet 28 grips the stud bolt 1b of the tool 1. The collet 28 is disposed at the tip of the draw shaft 27. The collet 28 is disposed in the collet chamber 23f.

[0023] The disc spring 29 is disposed in the spring chamber 23d and biases the drawbar 24 in the proximal direction. The unclamping ring 31 has a hollow cylindrical shape and is disposed in the center of the main shaft 23. The unclamping ring 31 may slide along the outer circumferential surface of the main shaft 23. As shown in FIG. 1 , the unclamping ring 31 has a pin hole 31a and an abutment surface 31b. The pin hole 31a extends radially and penetrates the unclamping ring 31. The abutment surface 31b is disposed at the rear end of the unclamping ring 31.

[0024] The ring pin 33 is disposed so as to pass through the pin hole 31a, the ring pin hole 23c, and the pin fixing hole 25e. The ring pin 33 connects the draw bar 24 and the unclamping ring 31. The ring pin 33 has a coolant flow path (second coolant flow path) 33a (see FIG. 1). The ring pin 33 reciprocates within the ring pin hole 23c together with the draw bar 24 and the unclamping ring 31.

[0025] As shown in FIG. 3, a pair of unclamping pins (triggers) 35 extend from the left and right (X direction) toward the central axis 3. The unclamping pins 35 have a head 35b and a pin 35a. The head 35b is fixed to the side plate 11d. The pin 35a passes through the trigger hole 21a and protrudes into the inside of the ram 21. When the ram 21 retracts, the pin 35a can abut against the abutment surface 31b.

[0026] As shown in FIG. 1, the feed motor 43 is disposed on the drive shaft support plate 11c. The drive pulley 51 is connected to the feed motor 43. The feed screw 39 has a screw shaft 39a and a nut 39b. The screw shaft 39a is supported on the ram support plate 11b via a bearing 32. The screw shaft 39a is supported on the drive shaft support plate 11c via a bearing 40. The nut 39b is inserted into the nut hole 19b and fastened to the connection block 19. The base end of the screw shaft 39a protrudes rearward from the drive shaft support plate 11c. The driven pulley 49 is fastened to the base end of the screw shaft 39a. The endless belt 52 is wound between the drive pulley 51 and the driven pulley 49.

[0027] As shown in Fig. 2, the main shaft motor 41 is installed on the drive shaft support plate 11c. The driving pulley 47 is connected to the main shaft motor 41. The driven pulley 45 is disposed at the base end of the drive shaft 15. The endless belt 48 is wound between the driving pulley 47 and the driven pulley 45.

[0028] 3, the coolant device 55 is connected to the supply port 15d. The coolant device 55 supplies the coolant to the machine tool 10. The coolant is, for example, a liquid coolant, a mist coolant, or a gas coolant.

[0029] The tool 1 is attached to the spindle hole 23g by a tool changer (not shown), a robot (not shown), or an operator. When the feed unit 38 feeds the ram 21 toward the tip end, the draw bar 24 is pulled toward the base end by the disc spring 29. Then, the collet 28 grips the stud bolt 1b and brings the tool 1 into close contact with the spindle hole 23g. The feed unit 38 further feeds the ram 21 in the tip direction, and the tool 1 attached to the spindle 23 processes the workpiece. The tool 1 performs, for example, milling, drilling, or tapping.

[0030] When the feed unit 38 feeds the ram 21 in the base end direction, the abutment surface 31b abuts against the unclamping pin 35. When the feed unit 38 continues to feed the ram 21 in the base end direction, the unclamping ring 31 is pressed by the unclamping pin 35. Then, the draw bar 24 moves forward relative to the spindle 23 against the elastic force of the disc spring 29. This causes the collet 28 to release the stud bolt 1b and push the tool 1 out of the spindle hole 23g.

[0031] According to machine tool 10 of this embodiment, simply by having feed unit 38 feed ram 21 in the base end direction, draw bar 24 advances relative to spindle 23, and tool 1 can be unclamped. Then, simply by having feed unit 38 feed ram 21 in the tip end direction, draw bar 24 can clamp tool 1. Machine tool 10 has a simple structure and can replace tool 1. By further feeding ram 21, machine tool 10 can perform drilling, tapping, milling, and the like. The unclamping pin 35 is disposed directly on the frame 11. This allows the force with which the disc spring 29 pulls the drawbar 24 to be increased.

[0032] Both ends of the drive shaft 15 are supported by the bearings 14 and the main shaft 23. This suppresses circumferential runout of the drive shaft 15. This allows the rotation speed of the main shaft 23 to be increased.

[0033] 3, coolant supplied from supply port 15d passes through coolant flow paths 15c, 25c, 33a, and 27b and collet 28, and is then supplied to tool 1. Therefore, machine tool 10 can supply coolant to the machining point through the tool holder, from the tip of the cutting edge of tool 1, or from between the cutting edge and the tool holder. The support shaft 15b is supported by a guide block 26. The guide block 26 is integrated with the draw bar 24. The coolant passage 15c is directly connected to the coolant passages 25c and 27b of the draw bar 24. Therefore, the coolant passage 15c has few connecting portions and little change in cross section. This reduces pressure loss of the coolant. Furthermore, if the coolant is a mist coolant, separation of the mist is suppressed.

[0034] <Embodiment 2> 4 to 6, machine tool 100 of this embodiment has a ram 121, a guide block 126, a draw bar 124, and a trigger block (trigger) 135. Other configurations of machine tool 100 are substantially the same as those of machine tool 10 of the first embodiment. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

[0035] The ram 121 has a trigger hole 121a. As shown in FIG. 5, the ram 121 has a pair of trigger holes 121a in the left-right direction (X direction) with respect to the central axis 3. The trigger holes 121a penetrate the ram 121 in the up-down direction (Y direction). As shown in FIG. 6, the trigger holes 121a extend in the front-rear direction (Z direction). The other configurations of the ram 121 are substantially the same as those of the ram 21 of the first embodiment.

[0036] As shown in Fig. 4, guide block 126 is a hollow cylinder and is integral with main shaft 23. Guide block 126 has guide hole 126b. Guide hole 126b extends along central axis 3. Guide hole 126b supports support shaft 15b. Support shaft 15b slides axially relative to guide hole 126b.

[0037] The draw bar 124 has a draw block 125, a draw shaft 27, and a collet 28. The draw bar 124 reciprocates inside the spindle 23 independently of the guide block 126. The draw block 125 has a body 125a, a coolant passage 125c, a shaft support hole 25d, and a pin fixing hole 25e. The body 125a is separate from the guide block 126. The coolant passage 125c is substantially the same as the coolant passage 25c in the first embodiment.

[0038] As shown in FIG. 5, the trigger block 135 is U-shaped in a front view. The trigger block 135 is disposed on the base plate 11a. The trigger block 135 has a pair of triggers 135a and a connecting block 135b. As shown in FIG. 5, the triggers 135a are rectangular plate-shaped. As shown in FIG. 5, the triggers 135a extend in the vertical direction (Y direction) and pass through the trigger holes 121a, respectively. The connecting block 135b connects the pair of triggers 135a and is fastened to the base plate 11a.

[0039] According to machine tool 100 of this embodiment, the second moment of area in the front-rear direction (Z direction) of trigger 135a is large. Therefore, the elastic force of disc spring 29 can be made even larger than in machine tool 10 of the first embodiment.

[0040] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present invention, and all technical matters included in the technical ideas described in the claims are subject to the present invention. The above-described embodiments are preferred examples, but a person skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents disclosed in this specification, and these are included in the technical scope described in the appended claims. [Explanation of symbols]

[0041] 10, 100 machine tools 11 frames 21, 121 Ram 21a, 121a trigger hole 23 Main axis 23c ring pin hole 24 drawbars 35, 135 trigger 38 Feeding unit

Claims

1. The frame and a hollow ram reciprocably disposed on the frame, the ram having a trigger hole extending radially through the ram and axially therethrough; a hollow spindle to which a tool can be attached and which is rotatably supported by the ram, the spindle having a ring pin hole which passes radially through the spindle and extends axially; a drawbar having a collet and reciprocating within the spindle, the drawbar being biased toward the base end of the spindle; an unclamping ring disposed radially outward of the spindle and connected to the draw bar through the ring pin hole; a trigger fixed to the frame and passing through the trigger hole; A feed unit for reciprocating the ram, The ram is advanced in a tip direction to machine the workpiece; the ram is retracted in a proximal direction to bring the unclamping ring into contact with the trigger, thereby advancing the draw bar relative to the spindle and opening the collet. A feeding unit; A machine tool having:

2. the feed unit advances the ram distally and retracts the drawbar relative to the spindle to close the collet; The machine tool according to claim 1.

3. The trigger is an unclamping pin extending perpendicular to the main axis.

3. The machine tool according to claim 1 or 2.

4. a ring pin that passes through the ring pin hole and connects the unclamping ring and the draw bar; The machine tool according to any one of claims 1 to 3.

5. The drawbar is a draw shaft connected to the collet; a draw block connected to the base end direction of the draw shaft; and The ring pin penetrates the draw block. The machine tool according to claim 4.

6. the main shaft has a spline hole disposed at a base end thereof; a main shaft drive shaft having a spline shaft inserted into the spline hole, meshing with the spline hole and transmitting rotation; The frame is a ram support plate that supports the tip end of the ram so that it can slide in the front-rear direction; a drive shaft support plate that rotatably supports the main shaft drive shaft; having The machine tool according to any one of claims 1 to 5.

7. a linear motion guide extending in the direction of the main shaft and disposed on the frame; a connection block that is guided by the linear guide, is connected to the ram, and is reciprocable; Further comprising: The machine tool according to any one of claims 1 to 6.

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